It is an odd recommendation but I can't help but see Blues EXE being similar to Vidar due to the same VA and both are mysterious individuals who are rivals with the main character. Both are cartoony in some way but have serious moments as well and Rockman has a history of having elements being influenced by anime such as Gundam for example.
When watching Mikazuki in his Gundam, I get a lot of Guts vibe from him making me think that IBO is inspired from Berserk. Both of the shows encompasses political and realistic themes but the only difference is that IBO has mechas and Berserk has warriors and supernatural powers. Another note is that Mcgillis shares the same VA as Griffith and both are Char Clones.