9 Kingdoms 2017

Ready to play in a single or double-elimination tournament – either format is fine.

Regarding the tournament – based on the theme, the most optimal option seems to be the one used, for example, in Dota 2:
Invite 8 popular streamers (direct invite),
The rest – all willing participants – go through qualifications until 8 more players remain. Qualifications do not require mandatory streaming.