REX

REX is a playable character in Risk of Rain 2.

How to Unlock
REX is unlocked by completing the challenge "Power Plant". (Repair the broken robot with an Escape Pod's Fuel Array.) Only the player completing the challenge will unlock Rex.

The challenge requires the player to acquire the Fuel Array item at the back of the escape pod at the beginning of the game, and escort the equipment all the way to Abyssal Depths. Within the area, the player has to make their way to the top portion of the map via the geysers placed around the area, where you will find REX's model as an interactable. Interacting with REX with the fuel cell equipped completes the challenge, unlocking REX as a playable survivor in future runs.

Note: The Fuel Array occupies your equipment slot, but as long as you escort the equipment to stage 4, you can temporarily equip another equipment in prior stages to charge the teleporter and clear bosses without the Array's penalty. MUL-T is able to equip the Fuel Array and use Retool to 'store' the Fuel Array without suffering it's penalty.

Also, beware that the MUL-T and Acrid survivors are unable to obtain the Fuel Array solo, as they deploy without an escape pod at the beginning of the run.

Tips

 * The Primordial Cube can be particularly effective on REX as you are able to launch it into your Tangling Growth, ensnaring a large number of enemies at once which in-turn massively increases your total healing.
 * Walking backwards, jumping and using DIRECTIVE: Disperse at a downward angle can launch you quite a long distance in a desirable direction.
 * Using Seed Barrage resets the attack cooldown of DIRECTIVE: Inject, allowing you to attack much faster than normal.
 * It is highly recommended that you avoid Transcendence and Wake of Vultures when playing REX as these items can replace your health with Shields, a type of health which cannot be recovered from healing. This can totally cripple REX as his abilities Tangling Growth, Seed Barrage, and Bramble Volley take a percentage of your health, but you are unable to recover any of it by using Tangling Growth, DIRECTIVE: Inject, or Bramble Volley.
 * It is highly recommended that you avoid Brittle Crown when playing REX as at least one of your four skills will cost health to use, causing you to lose most, if not all, of your money with every use.