Absorb: As a Slime, Rimuru was capable of consuming anything his body was able to envelop, and he sustained himself on the energy taken from that which he consumed. He retains this ability as a Reincarnated Devil, turning part of his body viscous to cover and absorb even sentient creatures. Whatever he absorbs is remembered by his body, and as long as he has the power to do so, he is able to replicate the abilities of things and people taken into his body.
Self-Regeneration: As a Slime, all of Rimuru's cells are all identical. This allows him to regenerate any non-lethal damage done to him as long as he has enough energy to do so. Paired with his immunity to physical injury, Rimuru has been classed as a nearly immortal being.
Physical Immunity: Even in his humanoid form, Rimuru still has the body of a Slime. Because of this, he has an absolute immunity to physical injury. This is accompanied by a lack of feeling any semblance of pain.
Thermal Fluctuation Resistance: Rimuru's body is also immune to changes in temperature. This gives him a certain level of immunity against things like fire and ice being used against him.
