There are actually three different "Episode 77s" depending on which Dragon Ball series you are watching. 🐲 Dragon Ball (Original)
Goku, bored with peace, visits Grand Zeno to remind him of the "all-universe" tournament he previously promised. Dragon Ball (Dub) Episode 77
The Grand Minister announces the "Tournament of Power," where 10 warriors from each universe will compete. It is later revealed that losing universes will be erased. There are actually three different "Episode 77s" depending
Piccolo finds a dying Namekian warrior named Nail. They perform a "Namekian Fusion," merging into one being with vastly increased power. It is later revealed that losing universes will be erased
Back at the main battle, Vegeta believes he has become a Super Saiyan and challenges Frieza. They appear evenly matched until Vegeta arrogantly demands Frieza transform into his next form.
I can provide more details on the English Dub voices or specific fight scenes for any of these! Dragon Ball Super Episode 77 Spoilers