Originally Posted by Xpecial
It's nothing to worry about, they took it out.
Basically before, it was an alternative to Ultimate Mode which boosted your melee speed and cleared a huge area of projectiles (like the current Ultimate Mode) that slowly drains your VP after activation.
They took out Valkyrie Mode and now they have Booster Mode.
wait wut.? how to activate that booster mode or something.? @_@