If you played Elsword, you might see some familiar faces.

So he decide to raise his own heroes to kill. But he whoops ass too easily and get no exp. So MC try to change his fate by trying to become a demon god, but he need to defeat strong heroes to get exp. Ni Xi Ba Mo Wang!/ Demon King's Counterattack!: Demon king suppose to get kill by heroes. Overlord (anime): Game get shutdown, but he and his NPC get summon to another world and they become alive. His shield can evolve and his class suppose to be weak (no offend ability), so I'm not sure how you feel about that, but it a really good series. He get framed and antagonized through out the series. Tate no Yuusha no Nariagari/Shield hero: Summon to another world (have some RPG like setting).

Because he beat the boss, he became super OP and add in the game world 500 years later, all the mobs become weak too. The New Gate: Start off like Sword art online death game (manga start off at the end boss), but he get teleport to the game world (everything became real) 500 years later. Toaru Ossan no VRMMO Katsudouki: Choose underdog class and skill and made it powerful, slice of life style/adventuring(no kingdom on fire. It not complete, but you might like some of these RPG theme manga/manwha

Legendary moonlight sculptor kissmanga