The name might be terrible, but my original concept for a navi might be acceptable now.
Normally light blue eyed navi that is relatively intelligent and easy-going. In battle literally tears off his arm and uses it as a weapon becoming something closer to a berserker(eyes change red). The initial concept had him throw the arm as his sig attack, but under this new system it could work another way.
Sig Attack: Mood Change
Splitman's eyes become red and his personality changes as he tears off his left arm, cables dangling, and wields it as a weapon in battle. If in this state the reverse happens, his arm re-attaches (if it is still available) and his eyes shift back to blue as he becomes visibly calmer.
In effect this would be changing from a recovery type normally, who shot small shield-orbs at his opponents from his left arm and did repairs using it, to a intense berserker-like fighter, using his detached left arm as something halfway between a club and a flail.
What would people's opinions on this be? Obviously it hasn't been entirely worked out.
Oh yes- image