Infinite's mask is obviously a way to hide his face due to the shame he felt losing everything to Shadow. But also, considering how the Phantom Ruby works, the mask could also work to isolate him from the constant noise and fog it emits. Hearing that droning noise 24/7 would likely drive him insane (well, faster than having the Ruby fused to his body would). It's interesting to think of the mask as a sensory deprivation tool that keeps him separated from the real world while the Phantom Ruby drives him deeper into his escapist wish-fulfillment tendencies. A literal echo chamber strapped to his face.











