Well, the first one that came to mind was Shantotto

I have her personality and sadism, but MAN is rhyming every response is a bastard that gets VERY tedious

She only popped up for a handful of meme responses and while I did have fun, it was waaay too much work

In a similar vein, I also pulled out a Professor Layton for a trial

He was a little too hard to make compelling. He's a great character, but you really have to have a love for the series and a setting to have for him to make him work

Haha, and I also tried Serenity, the firefly from Homestuck

These were all my weird ones that I really only got to play in memes and the like, so I don't know if they counted

If we're talking about characters I placed in a game and played for more than memes.... hmn...

Agrias Oaks I tried but couldn't make work. Reserved knights are hard to get out there and get to develop CR

Rose Lalonde really stretched my RP but that was mostly because I played her as my fourth major character, ad it was a bit swing at the time

And the most recent was Makoto Niijima, it was a personality thing, and it is hard for me to maintain a sense of distant aloofness