The best thing to do as a bomber.
Kiting: The tactic of circling a monster in hopes of making it sick.
In phases 3 and 5, Vana's fireballs act as a wall for projectiles (Shards). If you kite Vana and stay kiting while using RSS, you get a lot of damage output-- As much as half a Blitz charge.
The only thing negative about kiting Vana is the shadow fire that might land next to him while you kite. Also the chance you mess up and instantly die.
Could more easily die, also much harder, but...
As much as HALF a Blitz Charge?!
Metagame, watch out!