The untouchable challenge is one of the more difficult achievementsRisk Of Rain Returnshas to offer. You need to reach the third teleporter without taking a single instance of damage. Increasing the challenge factor, you need to do this playing as the Commando, who has limited tools for avoiding combat.
There will always be some level of randomness to the roguelike game, but a good strategy can make completing this challenge more consistent, if not a guaranteed success. There are several ways to ease this challenge and unlock the mace replica, a nifty equipment that can slot into several character builds.

Commando Loadouts For The Untouchable Challenge
The remake offers Commando a trio of alternative skills replacing their non-primary abilities, but all three are worse for completing this challenge.
Secondary (damage)

Full Metal Jacket
Combat Knife operates at close range, greatly increasing the chance you take an errant blow. Full Metal Jacket, on the other hand, can be used for hit-and-run tactics that aren’t great for timed playthroughs but have minimal risk of taking damage.
Third (utility)

Tactical Dive
Tactical slide lets you continue firing while in motion but doesn’t provide theinvulnerability of a tactical dive. Certain enemies will be near impossible to dodge without some lucky items or by using a tactical dive.
Fourth (special attack)

Suppressive Fire
Suppressive Fire doesn’t have the power of Point Blank butcan be used at a much greater range, minimizing the chance you get hit.
Fall damage counts as being hurtin this challenge, so Tactical Dive can be used just before landing to negate this.
Artifacts For The Untouchable Challenge
Artifacts can make the challenge a good deal easier, although you may prefer to attempt the challenge without them for an added challenge. Here are some of the most significant onesartifacts for this challenge:
Notes
Glass
The artifact of glass gives afive-fold damage multiplierat the cost of 90% of your max HP.
Since the goal is to complete the challenge without taking any damage,this trade-off has no downsideand can make it easier to identify when you’ve taken damage, as you’ll normally die instantly.
Kin
The Artifact of Kin forces each stage toonly spawn one enemy type, including teleporter bosses.
If the teleporter bosses obstruct this challenge, the artifact of kin replaces them with a horde of lesser enemies.On average, this will beeasier than a conventional boss, but the missile-firing elites can easily invalidate the untouchable challenge if you’re unlucky enough to fight a swarm of them.
Command
You canchoose what items dropwithin each rarity category.
Picking updamage-boosting and evasion itemswith no chance of getting useless healing items means you’ll be a lot stronger.
There is a slight vulnerability in thatyou’ll be forced to stand over dropped itemsto access the command interface. Any enemy nearby can hit you at this time to invalidate the achievement, so make sure to clear all nearby enemies before collecting loot.
Sacrifice
Containers no longer spawn, but enemies have a chance to drop items.
The artifacts ofSacrifice and Kin can trivialize many achievements. Restart the first level until the artifact of kin spawns an enemy type that poses no threat, such as stone golems or jellyfish. Then position yourself somewhere they won’t be able to attack you and continuously kill them for items.
Certain artifacts can make the challenge significantly harder. The artifact of Enigma can lock your active item onto one thatforces you to take damage, such as the lost doll. The artifacts of Spirit and Spite make it easier to take damage.
Strategies For The Untouchable Challenge
Completing The Untouchable Challenge In Single Player
The phrasing of the challenge is rather specific: You need toactivate the third teleporter, but you do not need to complete it. This means that you have to defeat a minimum of two bosses across the first and second levels and then run away from everything in the third level until you find the teleporter.
Slower strategies, such as hit-and-run attacks, can whittle down enemies. The timer will punish this, but not severely, for the first two levels.
If you are not using theartifact of kin,you’ll need strategies for dealing with the bosses at the first and second teleporter.
Strategy
Wandering Vagrant
The wandering Vagrant has avery consistent attack patternthat can be evaded by just moving in a line whenever it releases orbs. The risk posed by the vagrant is thatdodging it can force you into other enemies.
Colossus
The Colossus poses no threat as long as youkeep your distanceandwear it down with ranged attacks. It willspawn lesser enemies, but these shouldn’t present any legitimate risk at a distance.
Magma Worm
The hardest of the first tier of bosses, but the magma worm’s attacks can be dodged using the environment. If youclimb on a rope or vine you cannot be damaged by the worm.Stay close to one and use it to hide whenever it’s about to come up.Beware of Lemuriansthat can follow you up the ropes.
Ancient Wisp
The Ancient Wispcan be defeated at long range. Most maps it can spawn on will have spaces where you can outrun or outrange it. (set your zoom to 1x in the options if you haven’t already).
Its lightning strikes can be dodged, butspawns wisps on top of you.
Lynx Totem
The lynx totem’s continuously spawning minions pose a serious threat to untouchable runs. Theranged attacks of lynx tribe archerscan hit you while hiding in positions you’d normally be able to avoid all damage.
You need to be more proactive in this boss fight and keep clearing the more dangerous minions as you wear down the boss from a distance.
Completing The Challenge In Multiplayer
Testimonies are mixed on whether the achievement can be unlocked in online play, with some players reporting it working and others needing to complete it in single-player.
The Sniper Achievement Empty Pockets is more specific in its wording of “without any player collecting items or equipment,” suggesting otherchallenges without this phrasing should work in multiplayer.
It may be a viable strategy for the Commando player to host a lobby and then allow their friends to handle all the combat while they focus on survival.
In this case, the engineer and sniper are both good companions for completing this challenge. The Engineer’s turrets do a good job of taunting normal enemies, while the sniper can easily clear bosses before they can pose a risk to the Commando.
Reusing These Strategies For Other Achievements
There are variants of the untouchable achievement available for other survivors. They can be completed with broadly the same strategy, requiring a couple of modifications depending on the survivor’s toolkit and the specifics of the challenge.
Huntress’s Sixth Sense
Defeat the Ancient Wisp without taking damage.
The huntress doesn’t have the Commando’s tactical dive but is otherwise better suited tofighting at long distances while running.
Miner’s Blazing Victory
Survive a teleporter event without falling below half health.
This challenge would be easier if the miner weren’t a melee-only survivor.Swap his basic attack for Throwing Axes.
Miner’s Hot Streak
Reach level ten without taking damage more than once.
The kin-glass-sacrifice artifact comboallows you to complete this challenge while only facing one type of enemy. Stone golems and sand crabs will both struggle to hit you without supporting enemies. Find an elevated position they can’t spawn on and throw axes down.
Han-D’s Like New
Beat the third stage without falling below 60 percent health
This is less strict than the others but expects you to go further. Han-D doesn’t have a ranged option butcan pick one up for their equipment.