Fang Pi, Junkz, and Uppers can work very well (for KO and walling). I'm not sure how skeelz will work for you. Beck and Nina is always a go to for skeelz half for me, but with frozen i'm not too sure. I suppose if you go only 3 skeelz you can use plunk, redra, and Galactea. not sure on the other ones.