First Innate Spell
Eren was bewildered too. He couldn't make heads or tails of what was happening to him or his unintended victim. But in the next second, the hand that had grabbed Renar's almost melted wrist also turned dark green and had crocodile-like scuts over it.
Eren couldn't think of what to do or react next. So he activated his F-Rank Sedated Perception to buy himself some time.
'What is this? Reen, you have any idea?'
Reen pondered for a moment before replying:
This seems to be the innate spell that I use to digest my food. How did you learn it?'
Eren smiled mirthlessly in his head before responding:
'Hehe. Beats me. I didn't feel like I was casting a spell either. It was as natural and effortless as breathing.'
Reen thought of something and asked her master to confirm:
'Erni, do you think demi-humans have inherent spells of the beasts they have absorbed the bloodlines of?'
Some sort of understanding dawned on Eren after Reen made her line of thoughts known to him.