Megaman Battle Network Black OX.

[Kosheh]

yeeeikes. That Japanese logo is kinda...huge and seems kinda out of place given past Rockman.EXE logos.
I'd go with writing "BLACK" in Katakana ロックマンエグゼブラックOX
or, if you insist on using the kanji letter, maybe put the OX under the kanji, like this

I made this in like 1 minute in Photoshop, so don't use this lol.
Especially because I just realized it's "OX" and not "DX"
But I think this is enough for you understand what I'm talking about

also, your backstory reads a little...rough. I'll take a look at it later and see if I can clean things up if that's OK with you?