Thanos The Inevitable

+1: You gain one Thanos avatar token. You may only have one Thanos avatar, but you can use this ability even if you do.
+1: Gain one of the following artifacts: Power stone Mind stone Time stone Space stone Reality stone Soul stone
-20: You may only use this ability if you possess all 6 stone artefacts. Destroy your opponent and any cards they owned, provided {x} > 10