Update to this:
This is a bug with Siphon Bullets, it applies to all characters and also works on other players.
A player with 0 hp cannot die. gaining any health from items or urns adds to their 0 and removes the effect until they die again.
In theory this wouldnt really work in game, but is...
found this using Mirage but I think it is just an issue with the Siphon Bullets item.
Since it permanently steals HP every time it kills a hero you can bring the dummy Seven and Infernus' max health lower until they dont have a health bar anymore. While like this the dummy can still take...