Legendary Planeswalker — Gideon
+1 : Until your next turn, prevent all damage target permanent would deal.
0 : Until end of turn, Gideon 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 you have Gideon's emblem in a Two-Headed Giant game and control a Gideon planeswalker, your team can't lose the game and the opposing team can't win the game. If your teammate controls a Gideon planeswalker but you do not, your emblem's effect doesn't apply.