This is Grunt's loyalty mission, in which he requests that Shepard travel to Tuchanka so that he may complete the krogan rite of passage.
In the cargo hold of the Normandy SR-2, Grunt will pace back and forth restlessly as he tells Shepard that he is unnerved by his intense desire to destroy and kill. It has become an involuntary compulsion rather than an intentional, pleasure-seeking activity. He requests that Shepard take him to Tuchanka, as EDI is lacking in the area of medical records pertaining to krogan, who now fiercely guard their medical data since the salarians used it against them with the genophage.
All of the enemies in this mission are armored, and most of them aggressively attempt to close to point-blank range. Powers for stripping armor and stopping krogan regeneration, along with the various ammo powers useful against armor, are all things to look for in a squadmate. Consider upgrading Grunt's Incendiary Ammo to share with the whole squad. Crowd control powers to prevent enemies from closing to point-blank range may come in handy once you've stripped their armor.
It's also a very good idea to go into this mission with the heavy pistol upgrades for bonus damage to armor and critical hit, as with those upgrades the pistol becomes the most effective weapon against most of the enemies in the level, even in the "boss" encounter near the conclusion of the mission. The sniper rifle upgrade for bonus damage to armor is also useful if you carry one.
With Grunt in your party, speak with the current leader of Clan Urdnot, who is either Shepard's old friend, Wrex, or (if he died on Virmire or was never recruited) his brother, Wreav. Either will note that Grunt is not sick, he is of the age where he must complete the krogan rite of passage, and refers the party to the clan Shaman. The clan Shaman will relate various information about the rite, as well as krogan history and culture. Gatatog Uvenk will protest Grunt taking the rite, as he is tank bred. You can get Uvenk to stand down in a number of ways. After Shepard agrees to be Grunt's krantt, the Shaman sends Grunt and company to the traditional grounds of the rite.
To begin each of the three waves of the Rite, you will need to activate the "keystone" that's near the central stairs where Shepard is standing when you enter the area.
Before beginning the first wave, take a moment to run bypasses on the turbine parts on either side of the central stairs, get the platinum, and salvage the credits from four dead krogan on the upper level (+12,900 credits total). There are also three Med-Kits and two power cells.
Insanity Tip: It is best to leave the power cells and medkits where they are until you need them. However one power cell box and one medkit are on the lower level - you may wish to collect them before the third wave starts. Finally, as soon as you beat the third wave you will no longer be able to loot any of the objects, so be sure to get them all picked up before that happens.
Remember to get all of your ammo powers equipped - preferably Incendiary, Warp or best of all Armor Piercing. Also before hitting the keystone, you can take this time to scout out the area and note the locations of ammo cartridges, all of which will respawn repeatedly throughout the rite. Grunt will "helpfully" remind you to hit the keystone precisely every fifteen seconds when you are between waves, just to keep you from getting too distracted.
Varren - The first wave summons multitudes of varren and they all descend upon Shepard, Grunt and the third party member. Since they can only attack at melee distance, they should all be dispatched at range. They come from two sides of the map at the opposite corners from the switch, so you need to stay sharp and not leave your back unguarded.
Insanity Tip: Get the armor stripped off each varren as quickly as possible so that you can then use powers to slow down their approach. Be careful with Shepard's powers however: Varren are quite fast, fast enough to outrun powers with slower moving projectiles such as most biotics or Incinerate. Time and aim powers carefully to avoid getting juked, or use a power with an instant effect such as Neural Shock or very large area of effect such as Shockwave to compensate. This isn't an issue with squad powers as those are instant.
Note: It is possible to face the varren all from one side if Shepard quickly makes it to the middle of the center set of stairs (it's really a bit to the right of center). The varren will all come up at Shepard up from the bottom of these stairs as it is the quickest route to Shepard and the team.
Once all the enemies are down, Grunt will begin reminding you to hit the keystone. Before you do that, walk around and refill all your ammo.
Klixen - These fire-breathing creatures make up the second wave and are delivered by Harvesters on either side of the map; don't waste your ammo, the Harvesters cannot be killed. The klixen will need to be taken out while you are still out of their fire-breathing range or they can quickly cause havoc and deal a lot of damage. They are resistant to Incendiary Ammo and Incinerate (but their armor isn't) and they're weak against Armor-Piercing Ammo, Reave and Warp Ammo.
Insanity Tip: Once you've stripped their armor, abilities like Grunt's Concussive Shot or Jacob's Pull can stop the klixen before they get too close.
Tip: If you watch your teammates carefully, they will automatically face the direction of the next incoming harvester.
Tip: Unlike Varren, Klixen are quite slow and you can easily stay out of range of their attacks by continuously moving and shooting. Your squadmates will have to be ordered to do this or they will stand and fight (and often die) but Shepard alone can beat this section simply by continuously moving and shooting/using powers while picking up respawning thermal clips. Downed squadmates will automatically revive at the end of this (and all other) waves.
Once the klixen stop coming, Grunt will again start reminding you to hit the keystone. Refill your ammo before you do so, and consider collecting the medkit and powercells that are down on the lower level before you begin wave three -- they will be difficult to collect during the upcoming battle.
Thresher Maw! This is not so much a wave as it is a giant creature attack. There is only one Thresher Maw and the primary objective is simply to survive. All you have to do is survive the attack for five minutes and the test will be ended, though there are additional dialogue accolades if you succeed in taking it down.
If you manage to kill the Thresher Maw, you gain the respect of the krogan and the rite ends. The Thresher Maw moves around the outskirts of the map, but its trail of flying dirt clods is easy to follow when it dives back underground. The Thresher Maw can destroy the "merely metal" structures, so try to avoid those for cover and go for the sturdier stone/concrete pillars and walls instead. Its acid spit is an area of effect attack and will accurately shoot at you even if you're cloaked. Its blue "tongue" seems to be a weak spot, and incurs more damage than its armored carapace.
Combat Strategy: There is one indestructible stone pillar on the low ground area of the level—to the right as you face out from the keystone—that you can use to take cover from the Maw from any direction it might appear. Additionally, there are two respawning thermal clips at the base of this pillar as well as easy access to a Medi-gel and power cells on the higher ground that you can pick up from the edge of the raised area without needing to climb up. This is without a doubt the optimal place to fight the Maw, as all other locations will involve considerable running about when the Maw moves. Place your squadmates in cover behind the other two indestructible pillars on the high ground and they should also be safe and might even draw the Maw's fire giving you free rein. If a squadmate does go down it's not the end of the world: Shepard alone is more than enough to beat the Maw even on Insanity.
- The metal pillars can be destroyed by the Thresher Maw in one hit, but any cover made of stone/concrete is not destructible. You should always try to interpose indestructible cover between yourself and the Maw. The Maw's spit projectile does have an area of effect so try to be as completely in cover as possible when the Maw attacks to ensure you are not hit.
- Shepard's shields take longer than usual to recover after an acid hit, so be careful. On the plus side it takes about three consecutive hits to kill Shepard even on Insanity. Don't hesitate to use a Medi-gel to quickly restore your shields (provided you have the Emergency Shielding Medi-gel upgrade).
- A well-upgraded heavy pistol is more than sufficient to take out the Maw as long as you take advantage of respawning thermal clips to keep replenishing its ammo.
- On Insanity, the Thresher Maw's sheer amount of health makes using Heavy Weapons inefficient. The best strategy is to utilize Armor-Piercing Ammo on the creature (Warp and Incendiary Ammo being reasonable second choices), and have your squadmates constantly help you in attacking the Thresher Maw with conventional weapons.
- Grunt's Concussive Shot, even though marked as ineffective against armor, if applied when the Maw surfaces will "stagger" the Maw reducing the number of acid shots it will take before retreating.
- Zaeed's Inferno Grenade, Mordin's Incinerate, and Samara's Reave are examples of good squadmate attacks to use. Using weapons with high armor penetration such as the Widow, M-76 Revenant, M-96 Mattock, or most pistols will help a lot.
- The Cain will usually only damage half the Thresher Maw's health on Insanity.
- The Thresher Maw is immune to the effects of Stasis.
After the Thresher Maw is destroyed or the timer hits the five-minute mark, the Rite of Passage is officially over. However, at that point Gatatog Uvenk and his krantt make an appearance. During the cutscene, Uvenk expresses that he is impressed by Grunt's accomplishment. He then seeks out a loophole that he believes will allow him to accept Grunt. Grunt, however, is not at all pleased by what Uvenk is saying as he would be treated little better than a trophy for Clan Gatatog.
No matter what conversation option Shepard chooses, they end up engaging Uvenk and his krantt. Uvenk has a barrier and armor that need to be taken down to kill him and there are four Gatatog Warriors with him. After the cutscene, be ready to take cover immediately and order your squad to do the same.
Insanity Tip: For whatever reason most of the krogan, including Gatatog, will move rapidly away at the beginning of the combat, so you will really only be dealing with one or two krogan attacking at any given time - concentrate on one attacker and obliterate it before it can get behind your cover. Warning: Summoning a Combat Drone on top of the krogan at the start of this encounter will backfire by making all the krogan bum rush your position instead of retreating like they normally would. You don't want that.
Note: If you have a heavy weapon with good area of effect and still have ammo, you can wreak havoc on the krogan by targeting them at the start of the engagement while they are all clumped together.
Note: There are two krogan corpses that can be searched (1200 and 900 credits) and two Medi-gel packs to be picked up during the fight against Uvenk, but you have to loot them before finishing the fight because you will automatically leave the area. One is located down the stairs by the medi-gel packs and the other is behind the last barricade where Gatatog and his troops are positioned. It is advisable to wait until most of the enemies are dead before going for this last one.
Once the final enemy falls, you will automatically return to the Urdnot camp and speak to the Shaman. The Shaman will welcome Grunt as a full-fledged member of Clan Urdnot and award you a shotgun damage upgrade. Once you're done speaking with the Shaman, the mission will end. Once the mission has ended, a discount will automatically be granted at Fortack's Database; if you speak with Fortack he will address Grunt as Urdnot's new warrior, or if Grunt is not present, he acknowledges Shepard as Grunt's krantt.
Mass Effect 3 Consequences
Grunt appears during Attican Traverse: Krogan Team provided he survived the suicide mission. At the end of that mission, if you choose to spare the Rachni Queen, Grunt will die if this mission was not completed.
After the mission is complete, the Urdnot Shaman sends Shepard this email, titled "To Grunt's commander", with what one might call a "request":
Grunt has joined Clan Urdnot and should be emotionally stable.
Will monitor krogan’s progress of societal acceptance with Clan Urdnot. Hopefully clan bonds will not interfere with loyalty to Shepard. Data regarding krogan clan politics useful.
- Experience: 750 (937)
- Credits: 30,000
- Cerberus Funding: 15,000
- Credits Found: 15,000
- Power Unlocked
- Grunt: Fortification
- Platinum: 2,000
The last varren or klixen standing in the waves before facing the Thresher Maw may turn "immortal": they won't attack, but they remain in aggressive stance and can't die when shot or punched at either. The klixen may even clip below the ground.
To get around this, either reload the game, or have a biotic squadmate use Pull, and repeatedly shoot the varren with your shotgun in an upwards direction, effectively blasting it out of the map. Alternately if you are on PC and have the console enabled, use the "KillEnemies" command. If successful, the Rite will continue.
- After this mission, if Shepard killed the Thresher Maw, several krogan will comment on the Thresher Maw Shepard killed, stating that it has not been done since Urdnot Wrex underwent the Rite himself.
- Upon returning to Tuchanka after the mission, should Shepard have killed the Thresher Maw, EDI will report that there have been numerous breeding requests directed for Grunt. Humorously (and to Grunt's amusement), there is also one for Shepard.
- During the fight with Uvenk, heading up the flight of stairs and examining the giant piston will reveal the words: "Lots of very small text put something interesting here or whatever" upside-down.
- Unused dialogue for this mission suggests that originally, Grunt may have considered Uvenk's offer and Shepard would be able to expressly forbid Grunt from joining the Gatatog clan, a decision that Grunt would later confront Shepard about when back aboard the Normandy. Among the dialogue are responses from both Shepard and Grunt depending on how Shepard would have responded to Grunt's complaint.