That felt really fucking abrupt and lost me for a bit. What whiplash lmao. I get it wants to get past the setup but at least make it last 2 to 3 chapters or make the transition better.
So it's basically like "Lv2 kara Cheat datta Moto Yuusha Kouho no Mattari Isekai Life" where the MC is weak for a second to realise how much of an asshole other people are, and gain invincibility right after.