@Morose since Isekai means "other world" it doesn't have to involve switching from earth to another world, but from a fantasy world to another fantasy world, too. Switching worlds some way or the other is the only necessary thing to qualify as Isekai.
@Senshougahara this one is good, MC is middle age and still doesnt act like some retard middle age yet. mc also strong, know what to do and what need to do
Wooooohoooo, DAM I ACTUALLY FELT MY BLOOD PUMPING FULL OF EXCITEMENT FOR THE FIRST TIME IN 10 YEARS. HOLY SHIT LOVE THIS MANGA SO MUCH. Fufufu... Ahahahaha...
Hahahaha. this is what happens when the evil D&D kingdom, populated by at best level 5-7 NPCs and the large majority Level 1-3, piss off the player character who's level is in their high teens and armed with the fancy magic gear.