Shitennou Sai Jakudatta Ore. Tensei Shitanode Heionna Seikatsu wo Nozomu - Vol. 3 Ch. 16

[flannan]

If only, I'm afraid that he will stay alive so he can repent for his sins or some other bullshit from author.
But he is dead, I'll be very satisfied.

Generally, transforming into non-human form carries a high chance of dying. Not because of the dangers of transformation, but because the authors aren't afraid of killing anything that doesn't look human.

Also, he chose a bad time and place for his plot. Because MC is here, and his yandere is here, and there is the war heroine too.
If he wasn't running out of sanity, he would have used a smoke bomb and escaped, and only transformed when in a safe place.

 

[CheesiBoye]

Furry anime omni man was not what I was expecting, but I doubt it'll be going the way he went