What Champion should I buy?

Got 6300 ip! Looking for a mobile, fairly high skill cap champion. I usually play high dps champions, high button spam champs, or a combination of both (udyr?) Already have: Ahri Akali Caitlyn Corki Draven Elise Fizz Jarvan Jayce Jinx Kha'Zix Rek'Sai (I love this champion, he fits everything I want. Its just that he doesnt have a high skillcap, and is very easy to play. Gets kinda boring ;c) Riven Shaco Thresh Vayne Warwick Yasuo Zed I main jungle, but all the other roles are fun.