I have a Bunch of them on my Current Ikemen GO Build in Three Categories
1. Normal Final Bosses
-Kung Fu Man MHX by ibukah
-Omega God Ryu and Omega God Ken, Both by Etalking
-Shin M. Bison/Shin Vega by Kamekaze
-Asura Rugal by Dick Buckus (Edited by Dusk)
-WannaKOF by Brergrsart
-Destiny Orochi by みかえる
-Lord (Boss) Mizuchi EX by ahuron (Edited by ???)
-Two Different Versions of Thanos, One Version by Mushypepito123 (WOF), the Other Version by Tigreegoods (MCU)
-Lord Oberom by Zero_Col
-Evil God by Flavio Camarao
2. Random by Masher_2 (Edited by Below273), the Final Boss of the Very Hard Difficulty
3. "Storyline" Bosses (They All Appear in Order, and Only on the Insane/"Impossible" Difficulty after Defeating Random)
-Angle Draw Sphere by pkrs
-Mirror Cube Square by YANMAR and Triangle Delta System by まじっく
-Shodan by Shaxer (Edit of Icon of April Fools, Not Seen Anywhere Else Other than the "Formerly-Used-to-be-Paid" Compilation MUGEN Infinity)
-The System (C-STM-00X) by 0 (Yes, This Build is a Simulation) [The Controller inside G.A.D.U]
-G.A.D.U [Mind] (Illuminati) by Fabulouss [The Demiurge Mind inside Mugen]
-Demiurge [Soul-Essence] by D [The Living Emptiness] (the True Final Boss of this Build)