INVERTED AND LEASHED: Once per game, when an opposing character would be KO'd by Sabretooth, you may instead keep that dial on its last non-KO click. If you do, after actions resolve heal Sabretooth 2 clicks and remove all action tokens from him.

If he were to KO a bystander token or something like Teekl, could he heal for 2 with his trait?

I am thinking no since characters and tokens like that don't have ko clicks.

Great question. < following thread>

Nothing official, but based on prior rulings about zombies and the white lantern ring, I believe you are correct. He cannot activate his trait against bystanders.

I agree. Should follow the precedent for those effects.