Kyrie is somewhat bland and simple, but she served her role really well in portraying Nero's personality and stance on demons, which is the main theme of the game, hence the name devil may cry, not meaningless social commentary.
Well that's my point actually she is a very bland character, Nero also imo outside of his cool arsenals. Compare to Kyrie, Kat actually did something.
Kat was meh, didn't have a distinct personality like Lady and trish. Sub-par like kyrie, at least kyrie served something. Dat ass.
If we only argue about ass, then I agree with you Kyrie>Kat. I agree Lady and Trish are better, but thats because they are bad ass Female character able to kill demons with ease.