Mc should be able to revert back his tongue. Whenever he removes corpse poison he never seems to worry about secreting poison after. Honestly the only time it made sense not taking a skill was the zombie world and the infection skill or whatever it was. That would have probably become bad if he ever used it in his world.

Anyone know if the author is referencing an actual manga or just a fake one

I’m curious if killing others increases their summon limit