There's a common misconception about Maze of Ith that it removes the creature from combat. This is not the case. Even though Geist's ability triggers on attacking and doesn't matter if it's still attacking when the ability resolves, using Maze of Ith (your own, since Geist has hexproof) on it won't make it not attacking. Maze just untaps the creature and prevents damage to and by it, no more, no less.
Interesting. So Necrite and kin still can use their abilities even if Maze of Ith untaps them, huh?