Controls for the ABS section:
S - Attack. You can time it right to string together a quick combo, but it won't help at all in this fight.
Shift, Z - Defend. You'll guard facing one direction as long as you hold this. It reduces damage taken
from most attacks. Obviously you'll have to be facing the direction the attack is coming from
for it to do anything.
A, Q, W - These are the hotkeys. You can set various skills and items to them.
D - This opens up the ABS menu.

Inside the ABS menu:
Left/Right Arrows - Switches between the skills/items lists.
Up/Down Arrows - Moves the cursor up/down the list.
A, Q, W - Pressing one of these will hotkey the currect selection to it. If the selection is already hotkeyed
to another key, it will erase it. I might change this later on, but I really don't see a need to have
2+ keys use the same item/skill.