Hello, can someone help me understand the tactics?
Is the objective to kill monsters, and after collecting items from the monster, a sigil-like star may appear when it disappears. Entering it will grant you a skill that will remove the seals placed on the cube above the chasm?
Is someone there keeping the boss from flying around, or is it important to run around the hole with him, as monsters also spawn around him periodically?
I've heard that you can cast this skill twice, and it's not the first time I've heard this, but I don't know how? Quick clicking doesn't help. 
Thanks in advance for any help.