Which AP Jungler is worth it?

Yo! I’m a currently climbing bronze guy, who plays a lot of jungle (sometimes support too depending on my mood). I play AD champs (my primary is Camille) and Tanks (Leona, cause praise the sun). But now I realise the fact that I must have more variety in my champion pool. And because I already have AD jungler Camille and Tank Jungler Sejuani and Leona, I thought I needed at least one AP jungler. (Most of them seems very fun too). So I’m asking, who’s the AP queen/king in the jungle?

1. In general?
2. To climb elo hell with?
3. When fully mastered?
4. To snowball with? So basically Nidalee, Evelynn, Elise or Diana? (fuck Akali I hate her). Thank you so much and please answer properly cause I need some guidance! :)