REX is a secret survivor to unlock in the game. Although the challenge is clear, the way you have to unlock him is quite unconventional. This guide will teach you how to unlock all skills for REX and the proper build to use in doing so, which will help you eventually beat the game.

REX Best Builds to Use

REX’s skills have a mix of decent multipliers for bursts and a reliable and consistent primary skill in Directive: Inject. On-hit builds are popular for his Directive: Inject ability and survivability items are mandatory for REX.

Aegis Item 1

Harvester’s Scythe, Predatory Instincts, Leeching Seed, Lens-Maker’s Glasses and Aegis

This item combination will help REX become indestructible even with all his self-inflicted damage abilities. The problem is that REX’s Directive: Inject skill only leeches for the last syringe fired so you have to make sure it lands on a target. Harvester’s Scythe and Leeching Seed will increase your lifesteal more but the Leeching Seed does not have a multiplicative increase so focus on Harvester’s Scythe more.

Aegis is the staple of this build and it is the one that puts your power level through the roof. This holds all the inefficiencies from your lifesteal and the natural leech from your abilities to good use. This will more than double your effective HP with just the Aegis and you can even stack more of it if you choose to. Tougher Times is also a great damage negation item to add just to avoid getting burst from unnecessary damage.

Another problem you will encounter is the lack of damage you will have in the later stages of the playthrough. Seed Barrage will be your burst ability to be used on elites, bosses, and clumped enemies. It has a high multiplier so adding a few Crowbars will still be efficient.

Soldier’s Syringe, Brilliant Behemoths, Kjaro’s Band and Tri-Tip Daggers

These items are common for strong on-hit builds for survivors that can land fast procs. This will help you increase your damage output even more with the constant damage from your Directive: Inject skill. You should still focus on the first build above before adding these items.

Once you feel that the build above starts lacking damage, you should slowly start adding on-hit items and maybe pair damage-dealing equipment with it like the Disposable Missile Launcher and add a decent amount of Fuel Cells to go along with it. Any item that can be potent can be added to REX because he is highly versatile.

Mobility is also an issue for REX because of his inability to jump over high cliffs and to move fast in general. Adding a few Paul’s Goat Hoof and Hopoo Feathers should be enough. Overall, REX needs so many items compared to other survivors.

How to Unlock Drill

REX Achievements

To unlock the Drill alternate skill, you should first complete the ‘REX: Bushwhacked” achievement. It is completed by finishing the teleporter charge while under 50% health. This challenge makes you play with fire because it teaches you how volatile REX’s playstyle is.

I recommend doing this challenge as early as stage 1 or 2 and if you are not able to finish the challenge, restart the game. This is because once you get your build going, it will be hard to hold your health under 50% for the whole duration of the teleporter event. Damage negation items and shields are great buffers to have for this challenge.

Tougher Times, Personal Shield Generators, Jade Elephants, and Topaz Brooches can all be useful to keep yourself alive without healing you above 50% health. These items are almost required to finish the challenge if you are not used to playing REX and you want to unlock your skills as soon as possible. Avoid using the Transcendence lunar item because having your health converted to shields will still put your health at 100% all the time.

How to Unlock Bramble Volley

To unlock the Bramble Volley alternate skill, you should complete the “REX: Dunked” achievement first. This is completed by killing a Clay Dunestrider on Abandoned Aqueduct by throwing it into a pit. There are a few conditions that are random which makes this a bit longer. The challenge should be easy to complete once all the conditions are set.

The first thing you should do is to finish stages up to 4. Every time you enter a new stage, pay attention to the environment. If you do not enter the Abandoned Aqueduct environment for the first 4 stages, you should restart your game already. Environment-specific challenges are quite a nuisance to do because of the random elements involved.

Once you have the Abandoned Aqueduct environment up, look immediately for the teleporter and start it. Spawning the Clay Dunestrider as a teleporter boss is another random element in the game that you need to happen. If it is not a Clay Dunestrider, just play the stage as usual and proceed immediately to the next stage.

Keep doing this every 5 stages until you cannot keep up with the enemies anymore and restart again. This makes you start again from scratch and hopefully, you can spawn in the Abandoned Aqueduct environment quickly. If you manage to spawn the Clay Dunestrider, do not try to kill him. Avoid damaging him so that this does not happen.

Run immediately to the north of the environment until you see a pit. There are two pits you can throw the Clay Dunestrider to. The one in the middle and the one on top near the secret boss that unlocks the Runald’s Band and Kjaro’s Band. The Clay Dunestrider is quite slow so you will have to wait a bit.

You do not need to charge the teleporter and leave it immediately and look for a pit. If you are lucky enough, the teleporter can spawn near the pit in the enviroment. If you are doing this at a high stage level, make sure to clear the enemies as you will be luring the Clay Dunestrider to the pit and it could be dangerous.

REX Tips and Tricks

  • Always remember that REX’s Directive: Inject skill only leeches life based on the damage of the 3rd syringe hit. If that does not hit, you will not leech any life naturally from Directive: Inject.
  • Health Shrines or Shrine of the Woods are important for REX in the early stages, especially on Monsoon difficulty.
  • Directive: Inject can be cancelled by Seed Barrage and can be activated again right after Seed Barrage is used
  • Always be careful when using Seed Barrage because it drains REX’s health massively and you might not notice
  • Directive: Disperse can be used when jumping because it has a knock back that can push you forward if you use it while aiming behind you
  • Directive: Disperse is used to knock enemies off the map for an instant kill
  • Tangling Growth will leech health from enemies even after they die


REX is the most volatile survivor to deal with and even has the most obscure challenge in the game to unlock as a survivor and it is explained more in this separate article. It will be hard to keep track of your health because of the Seed Barrage but once you get used to it, REX is extremely strong because of his flexibility.