Jungler Poll

Hi. I am a level 30 LoL player who plays a lot of jungle. I recently saved up to about 5,500 IP and am deciding on who to buy next. I have a couple of champions in mind and was hoping to get some feedback from the community. As of Patch 5.7, I know Sejuani is really good but for overall consistency which champ should I buy?

TL;DR Idk who to buy so vote in the poll (important to me) and comment (optional)

1. Shyvana
2. Sejuani
3. Trundle
4. Skarner
5. Vi
6. Diana