Last time got people got really mad at me for not providing certain information, so here it is. Build and all proofs in video.
Details:
No outside buffs at all - no allies, no food, not even low HP to double the effect of the Staff.
Talent Lv11 (Lv8 base +3 from C5)
Yes it's C6 Zhongli, although the only thing that does to Burst DMG is increase the Talent Lvl by +3. It does nothing else to damage.
It is R5 Staff of Homa.
My Artifacts aren't God-tier, and my Sands is HP% - you could get a bit more damage out of ATK% Sands I think. One person in the comments last time showed me higher damage with a lower Refinement Staff; I know it's possible, I don't think I am doing the most damage of anyone in the world lmao
It was never my intent to post this to show off my whaling, that's why I didn't include the details in the first place; I was just really happy to see such a big number and wanted to share. But people didn't like that, so here's what you asked for with all the details. I hope it's fun to watch. Thanks.