Which units have you always wanted?

For me, I’ve always wanted to have Yace or Ex Luffy.

I know that Yace has only just begun to age well, being able to beat both Sabo and Kuzan fairly easily, and while Ex Luffy is also not that great, he just looks like so much fun.

I hope one day I’m able to get both, but I feel like no matter how many rds I save, their banners rarely show up.