Mausy Plot Ideas!

I am all up for helping you plot, I only have three cats up right now and two in the idea stage, but I think a couple might offer some potential for you. I think Dovepaw is likely too meek for much to do with your cat, and Tigerkit, when he becomes an apprentice might enjoy trying to become an enemy, but might be just a bit too young to be a threat (though I'm all down for him trying anyways and getting his butt kicked)

My Riverclan warrior though might make a nice plot device for you~ He's not meek or shy, though he is rather quiet and anti-social. His strong presence and intensity might make up for that if you want a romance plot, he likely will be slow or hesitant to react, but has a lot of previous family conflict and inner questioning that I could see leading him to be more accepting then a clan cat should be of a loner, and a lot less likely to drive him out. The flirting can go quickly from seeming to have no effect to suddenly Nightchaser going along with it, and while he isn't one to be boisterous in personality, I sincerely doubt Mausbar will scare him off or overpower him, and they can probably keep even levels with each other
Or we could flipside it, since he's questioning himself a lot, I could also see him, if you want an enemy, turning on Mausbar as a loner to either prove himself or to fight himself, and becoming determined to seek Mausbar out to defeat him or drive him away permanently~

I also have a few unwritten chars as well, though as of yet none are of clan cats, but if any might hold interest it would probably be Mockingbird

Mockingbird is an older tom loner who has a lot of experience with the clan and is sortof gathering together a group of his family (loners and rogues from the clans, especially Riverclan) and is also poking around the clans in general, and he is a very social, strong personality, with smooth talking, bold ideas, and a bit of poly-amorous flirting to go around. So he could be perfect to either start a deadly rivalry with or find a love affair

side note, I'm down for any kind of drama or the injuries of cats in this, and these are just some passing ideas for you to look at~