Had a probably not-good thought about a revised Guardian Angel.
Will post it anyway because why not.
Guardian Angel
Chain Vest (800) + Negatron Cloak (720) + 880 = 2400
+40 Armor +40 Magic Resist
Unique Passive: Upon taking lethal damage, you vanish for 0.5 seconds before becoming a Guardian Angel for 3 seconds. During this time, you become untargetable and are unaffected by abilities from allied champions, your abilities have no casting costs, and any damage you would deal (including True Damage) is reduced to zero.
Your champion's other "on taking lethal damage" effects will be activated once Guardian Angel ends.
The idea is supposed to be that you persist for a bit as an entity that can provide support and CC, but can't body-block or deal damage to anything in that state.
I just think this thing should be more utility oriented than just giving free lives to any AD champions that have the luxury of buying it. It's already obnoxious enough having Zilean around doing that.