Towards the end of this game 56173448 I noticed that after maxing gutshot my game was freezing for a second every time I activated it... particularly in a fight at the end against the enemy graves...
If you have siphon and build up stacks from killing someone and later sell siphon it will drop your hp as expected, however the hp is not returned to the enemy even after killing you... after re purchasing siphon it has no stacks and the enemy is still unable to get the hp back