Yeah, um, harming/killing/bodyhopping Hikari is way, way, way too much for I think any game. I mean, the kid's like a day old at this point.

I'm not against "Quincy Shunko" as long as it is justified in usage and not broken up the wazoo. Quincy having melee techniques is fine. The only melee technique they have is based on a modification of ranged combat (Steele Schneiders). I think the development of Quincy melee techniques normally occurs as an evolution of ranged techniques. But if Rex is really more melee-focused in general, then it seems fine that he could find it by trying to focus Quincy abilities towards melee combat rather than it just occurring out of necessity.

Also, yeah, don't go too close to Final Form, as once you start getting techniques that are in that range of what the ability is doing you're probably getting too powerful. Especially since using Final Form literally overloads a Quincy's powers.