Hi guys

I'm trying to do the Xylem encounter now in Dragonflight, did him back in Legion so I know the fight well, I'm just having a lot of issues with phase 2 against the Corrupted Shadow. I just can't get it below 50% before the whole are is filled with void, even if I carefully shimmy along the edge as you were supposed to back then.

I'm using Crafted Dreadful Gladiator gear with strength gems as per Wowhead's guide from Shadowlands:
My gear consists of Prydaz, Insignia, Ravaged Seed Pod and Ghost Iron Dragonling. Also got Windscar Whetstone but didn't find it very effective dps-wise.
My weapon is a Primal Infused Drakebreaker's Greatsword. Haven't gotten around to getting anything better.
I am considering finding something low level to slap Crusader on.
I use consumables like drums, pots, phials, food and runes as per the guides instruction above.

I also noticed that the Corrupted Shadow uses an ability that isn't listed anywhere on Wowhead. Called Horrific or Horrible something, I sadly don't remember as it pops up and is gone pretty fast. It is possible to interrupt it however it seems.

Anyone here have tried this fight in Dragonflight and can give some tips or even confirm it's possible?
It just feels like its health pool is much larger this time around or the void spreads faster.