So I still don't have BR, this is my method of killing it. Gradeus had another method which is as good or better with PX BR WD, can check it out here: https://www.youtube.com/watch?v=PsfjAjHf5YY
Best was 859 but I'm pretty sure I can go higher - it's all up to Heimdall and if he wants to put up his shield, lol.
The Shadow Dash method from 3c doesn't seem to work for at least this abyss skill, so instead I used sixth serenade to mop up the rest of the HP, worked out pretty well.
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