Deadpool's T3 strength is in what the skill does to enemy defense values, not in the stat increases from T3 advancement.
Honestly, neither of those obelisks is optimal for DP. If you're going for PvE, you'll want something with a 200% damage proc (his current one is a good placeholder, though!). For PvP, it's GBI/whatever/5 sec invincibility.
Odin? He's way behind PvP meta these days & is in sore need of a uniform. If you play AC, toss the Invincibility one on him for now.