Mega Aggron is criminally underrated. Once you get those Iron Defenses up, your literally cannot be touched from the physical side.
Also, side note, in the last battle, that Mega Aggron was Max HP Max Defense, which allowed it to not only outstall Buzzwole, but also commit the endgame funni.
Link to the original "Can't Outstall The Wall" video: https://youtu.be/bNzBAWdkWfw
Heat Mob's "The Wall"
https://youtu.be/zpemKbWUqW0
Mega Aggron cry
https://youtu.be/pFFLnWV_Zqo
The full replays:
https://replay.pokemonshowdown.com/gen8nationaldex-1294864336 The Wall behind screens
https://replay.pokemonshowdown.com/gen8nationaldexuu-1294255652 "Oops, all physical attackers"
https://replay.pokemonshowdown.com/gen8nationaldexuu-1282195928 The showdown of the century
Link to the Ryan & Ditto Discord server:
https://discord.gg/pE52NStJfj