Here's a sequence featuring both Volo and Adaman from Pokemon Legends Arceus. The idea was suggested by TPoN.
"Volo, finally managing to get all of the elemental Arceus Plates, manages to take some of the power of a God himself! He begins to grow huge, skyrocketing to the peaks of Hisui, rising on the top of Mt. Coronet, easily outgrowing any Pokemon in sight, and even the peak of the mountain itself! He keeps on growing, due to just how much power he is able to get, and on the verge of dominating the region
Of course, people gotta put a stop to it, Adaman specifically! Perhaps with Dialgas help, he gives Adaman some of his strength and access to one of his moves, Roar of Time, growing Adaman huge as well, before Adaman fires off a Roar Of Time to reverse the growth Volo had been going through, shrinking him down as the Time is then absorbed by Adaman, making him as big as the region around them! Though, not with the intention of destroying it, instead, guarding it while trapping Volo on/under his bulge to make sure he doesn't get out of hand again!"
I think that pretty much works nicely as the description of the situation.
1. Volo towering over Mt Coronet after getting the power of the Plates...but his celebration runs short after being hit by a big, warm, cushiony thing.
2. Adaman grew thanks to the power of Dialga, and is there to stop Volo, his bulge being the pne that pushed Volo earlier.
3. Adaman grows as big as the Hisui region, safely covering everything, but making sure that Volo is kept "imprisoned" under his massive bulge.
Hope you like it!