It's "extreme" for a reason, to eat your lunch if you don't do job mechanics. I tank all the extreme primals because it's fun.

Nidhogg without cooldown on Ala Morn. You could die.
Sephirot without cooldown for his telegraphed fists, you die.
Sephirot without cooldown for towers, you die and likely wipe the party
Thordan add buster, you don't pop a cooldown, you die.
Sophia green buster, you don't pop a cooldown, you die. Oh and you get knocked back too so positioning is important.

You see the green, pop Shadowskin or Shadowall. Done. Foresight is also good when its up because the buster is physical. Other tank should have already voked and have threat when you get pushed back since you stop hitting it.

It's not tank-and-spank land, if you want that the fine normal modes are there for that junk.