(Juanuary 31ST 2025 UPDATE) - ADDED NEW FORM "SUPREME SEELKADOOM"

Seelkadoom is the main antagonist and final boss from the 2005 flash game/movie series on the websight "Newgrounds" called "Sonic RPG" made by user "MidNightMaren" And ran from 2005-2020 with a total of 10 movies (With episode 9 and 10 having game versions.) Seelkadoom is a fusion of sonic and shadow that was created by dr eggman by using sonic and shadow's battle DNA. His main goal is to concur the world and sometimes calls shadow and sonic brother (Due to him being made by sonic and shadows DNA.) When he uses the chaos emeralds but doesn't fuse with them he is plain unkillable and because of that super sonic and super shadow had a hard time fighting him. He would scale to multiverse level. https://youtu.be/xmRIJ2A2DDQ?feature=shared - SEELKADOOM THEME

He also has a transformation when using the chaos emeralds called "Apex seelkadoom."

And due to apex seelkadoom being negative chaos energy this is his dark form. And apex seelkadoom as actually stronger than hyper sonic but the reason apex seelkadoom lost was because apex seelkadoom is slower than hyper sonic. During apex seelkadoom and hyper sonics final battle hyper sonic would spare seelkadoom and he was returned to eggman.

(BTW HE HAS A HYPER FORM BUT IT'S FANMADE AND NON CANON BUT YOU CAN ADD IT TO YOUR STORY IF YOU WANT)

I have no idea what this "Supreme seelkadoom" Is lol (BTW I heard that seelkadoom is part of this thing where he has these teammates with nazo and other hedgehogs but I never heard of it because I follow the Sonic RPG canon since that is where he originated lol.)

IDK if it's stronger than APEX because apex seelkadoom is stronger than hyper so it might be weaker but idk. And just like hyper this form being added is your control