The black hole move that sucks you in and usually kills you in one hit, ways to counter that:
Build 100% Darkness resistance (Put on a shortcut, swap into it in the hole, and out of it after)
Use shard: Reflection Ray (worked for me waiting for his 3rd incantation and then activate)
Use shard: Directional Shield (absolutely the easiest, blocks the entire attack as long as held)
Iframes (Invulnerability Frames of moves). Various weapon tech moves has various amounts of iframes, also rank 9 double jump, high jump and invert have very small iframes. Requires precise timing.
Spamming jump kick or slide attack used to work on escaping the black hole, but was always highly unreliable, and might have been patched out now.