Yes but the point of this group initially is to fight hollows who are springing up around the world. It may progress into something later. It'd seem impractical at the least have him along unless they need to scout a very dangerous hollow or find a way into a building of people without alarming them. It's like wearing a stealth cloak from harry potter and carrying a dagger while everyone else has armor, versatility of various items, and or magical swords to put it in perspective.
Later we will progress into tougher and tougher enemies and the second they notice you you'll likely be alone against a boss in the case of your powers. If that's the case he may be out of luck if the others can't get to him in time. If Character is only able to cloak himself in a field that hides his presence from others and even to a degree his spiritual presence he'll quickly become more and more liable as the enemies get stronger and are able to detect people better and we rely on people who are more combat oriented than not.
That's not to say my character in himself isn't going to get weaker later on his style is predictable once you get his pattern down and he has next to no stealth skills but he'll be able to get faster, stronger, etc and able to keep up until we as a group get extra buffs. You're character's ace would be his stealth abilities which go into OP territory if taken to far. Poison + Practical complete invisibility will basically cause bosses to get scratched allowing poison to overwhelm them, because Pudding's character also specializes in poisons, then finished off with a quick smack to the face by the others in the group (my character, maybe lex's, and any NPC characters who happen to join us).
In clearer words this would be fights end game with a invisible character who can use poison: Sneak up on enemy while the tank is distracting them, scratch them, let the tank finish his job, medic pellets him with more poison, boss weakens, tank eventually starts to wreck the enemy boss because he can hardly move due to his systems being practically overrun by poisons. Worst case the enemy is immune to poison and your character is just a annoyance who can make distractions while not dealing all that much damage. You're character's worth would be that of an scout instead of a soldier. I'm not saying you're character is over powered but that he'd make battles to cut and paste. Sneak in, sneak out, send team in, team does their thing, get out and repeat.
If you can prove me wrong by pointing to a specific shonen character who does the job in a way that would still allow you to be relevant late game then I may reconsider.