Legendary Planeswalker — Gideon
+1 : Until your next turn, prevent all damage target permanent would deal.
0 : Until end of turn, Gideon of the Trials becomes a 4/4 Human Soldier creature with indestructible that's still a planeswalker. Prevent all damage that would be dealt to him this turn.
0 : You get an emblem with "As long as you control a Gideon planeswalker, you can't lose the game and your opponents can't win the game."
If damage that can’t be prevented is dealt to Gideon after his second ability has resolved, that damage will have all applicable results: specifically, the damage is marked on Gideon (since he’s a creature) and that damage causes that many loyalty counters to be removed from him (since he’s a planeswalker). Even though he has indestructible, if Gideon has no loyalty counters on him, he’s put into his owner’s graveyard.