[Twan]

Mirror image as the level 9 air bless may even be usefull for glamour sacred if it's +1 mirror image, meaning ennemies have only 33% to hit the real unit in melee. But with the air shield in addition, air bless can become too powerful (like glamour units continue to be when arrow fend counters the glamour nerf).

I would prefer fly as an air bless (more original than one more offensive or defensive bonus, and making slow heavy sacred better candidates for a bless strat -living pillars or heart companion jumping in round 2 with attack:archers would be fun).