animu boss battle music
-Endless Despair https://www.youtube.com/watch?v=Lk1qatJy3w8 - this guy is cocky and also fucking haaaaaates you
-A Mighty Power https://www.youtube.com/watch?v=PPU0HD9hvmg - extremely epic-sounding, definitely a final boss theme or like, facing down this gigantic titan
-Yomotsuhirasaka (Gates of the Underworld) https://www.youtube.com/watch?v=a2pN_fyKotg - "an opponent that seems terrifying at first but is actually rather graceful"
-MUST DIE https://www.youtube.com/watch?v=Af6JRDhNBiw - angry engrish and japanese chanting, i don't even know what fits but it sounds scary
-Zinnia https://www.youtube.com/watch?v=GIn8_Q27WFY - Fight against a rival-type character? Not evil/threatening enough to be an actual villain imo but still good
-Tigrex https://www.youtube.com/watch?v=1X4CkFmeCl8 - relentless, savage, but still conquerable opponent
-World Champion Battle (Blue's Theme) https://www.youtube.com/watch?v=zrVw5rnwdrE - just a strong opponent, doesn't sound overly "evil" to me but still imposing
-Ghetsis Theme https://www.youtube.com/watch?v=LEbLAFHo5Ts - there's a weird break in the middle but it also kinda builds up the tension afterward
-Necrofantasia (dBu Remix) - idk but it's damn epic, also try the Demetori one if you don't like this
-U.N. Owen was her? (CtC version) - dramatic and crazy

also some standard battle themes
-You of the Dark https://www.youtube.com/watch?v=IwtmINMFAGU
-Strawberry Crisis! https://www.youtube.com/watch?v=Qwb2qUE63z4 - this works as either really but it's somewhat generic