After achieving True Blanco (not the fake one that Grandma Goku unlocked in the tournament) Gohan fought alongside Base Shaggy vs El Grande Padre.
They fought for centuries, destroying multiple Omniverses and the Chungus in the process, until it was revealed Daishinkan was just playing from the beggining... cause he was already
Blanco from the start. Then a shocking truth was revealed...
El Grande Padre is actually Black Goten from the Future, who fused with the Multiverse and swallowed all existence twice before killing Toribot and becoming Zeno's babysitter. This means he's inmortal beyond all of fiction and that all events of DB were staged by him from the very beggining.
This truth enraged Gohan, which made him achieve the ultimate state:
Calvo.
After this multiple timelines were born... but if Cell failed at contending El Hermano's debuff, then Blanco Calvo would not reach 100%, which would make the defeat of El Grande Padre impossible.
This created one of the greatest plotwists ever made in manga.