You should know
Coordination is the name of the game. If you’re an organized group on voice then have a leader call out the name of who they want to soak the next pillar. That lets the healer start prepping to heal them, keeps stacks spread out and improves your control over the fight.
If you’re in a pug then take on as much responsibility as you can yourself. Soak a pillar to 10-12 stacks, let them reset and then seek out another pillar. The more mechanics you handle yourself, the less your party has to do and you trust yourself more than the people you just met.
Ultimately this fight is a hard DPS / HPS check and even with perfect mechanics you may not kill him. Make sure you saved your 3 minute cooldowns and Bloodlust. You’ll need them.
The boss getting a Consume Charge cast off is doom. That’s what you’re racing against. He doesn’t gain any energy naturally so you can still him indefinitely with good pillar control (until your healer runs out of mana).
DPS will seldom realize how tough this fight is for you and even with perfect play you’re going to be pushing more throughput than anywhere else in BFA Mythic+. In general:
Stay mana efficient. You’ve been told mana doesn’t matter much in Mythic+. Tyrannical Galvazzt is a whopping exception. If you think you’ll need a strong mana trinket before the run starts then use one. Make heavy use of your efficient spells like Efflorescence and Essence Font.
Galvazzt is a heavy fight. I am the healer by the way.