I got this idea with the new vitasuit design.

It'd look like a vitapod, have no defense whatsoever, but really high health. equal to that of four similar tier plate or shell shields.

This would give it all around moderate defense.

if it's still OP, instead of being invincible, it could have 80-90% damage reduction or only heal when you run on top of hearts, thus healing both you and the shield

Mononoriyo and Elkirth helped with this idea.