PvE boxing - how to approach specific mechanics

Just starting a thread about how to approach spesific mechanics, bosses or content when PvE boxing.

I feel like there's a lack of resources that's being shared regards to the subject and wouldn't mind helping out if people feel like they're in a jam, I've certainly been a fair share of my own.

As such, I'd like to open the discussion regards few very specific encounters: ToGC25 Faction champions & Mimiron 10/25 man on hardmode.

Any suggestions, no matter how wacky are welcome, these bosses are being a big wall ATM and willing to entertain anything.

More spesifically: how should CC rotation and damage reduction / avoidance be tackled during faction champions.

How should fires be spread during first phase of Mimiron fight and how to survive the second phase with the fire in the ground and spreading being as difficult as it is.

Cheers

Ulduar Hardmode guide:
https://docs.google.com/document/d/1...4/edit?tab=t.0