"Phazing" is just flavor text, like "draining." It appears to actually be a different damage type in the game, named next to 'critical-hit,' etc, however it does not have any additional effects. The only enemy that uses "phazing" damage are the Vortexes, which are found in Battle 2, and do 145-203 damage.

Only top voted, non community-wiki answers of a minimum length are eligible