The Tl;Dr sounds interesting but looking deeper, I found some hangups.

Firstly, if there's no reason for players to kill each other in this death game there isn't much moral ambiguity to that conflict. The hunger games made it clear only one would survive in the end, which cast a seed of distrust between the contestants which drives quite a bit of the conflict.

I am therefore asking why this core element of the concept has been seemingly removed.

Secondly, the supernatural abilities. This is me advocating caution. Make clear limits what these supernatural abilities can and cannot do. Otherwise you make it very easy for people to make undefeatable mary sues.

Lastly, I would advise simply using dice rolls to resolve combat instead of using a clear cut system like D20. The system has its strengths. Players fighting each other is not one of these strengths.

My regards and hope we can make something good