A Summoner? - Chapter 23: Fall Festival Tournament Begins?

A decision can destroy the sun, moon and stars. A finger can kill the Heavenly Overlord. While chatting, the Heaven and ten worlds can be annihilated.

A poor little kid walks out from a remote mountain area while holding the Nine Dragons and the Incredible Cauldron. With a control over the time and space eternally, he embarks on the Path to God where he defies the odds of the boundless universe gaudily by fighting against royalty and clashing with the legendary generation.

- Description from Novelupdates

When a glowing portal yanks Leo from his struggling existence, he is saved by a mysterious system which gifts him new chance to break free from his side character experienceRebuilding an abandoned guild to honor his family’s legacy, Leo finds himself under the evil eyes of monsters, both from humanity and the gates he ventures intoin short : overpowered necromancer building a guild.

He was supposed to die in the academy dungeon.Instead, Earth’s greatest war hero opens his eyes as Velorum’s most hated student—the “villain” everyone expects to be executed by midterms.Swordsmen duel, mages burn, saints bless, tamers command beasts. He, unfortunately, practices the one art people fear most: necromancy. He doesn’t want a throne or revenge; after a lifetime of medals and funerals, he wants something scandalous for a villain—to live well. To laugh after curfew, to taste street food, to keep the friends who chose him alive.But the church wants a heretic, the crown wants a scapegoat, and the academy’s golden hero can’t explain why the “villain” keeps winning.Call him monster, call him traitor—he’ll carve out a life worth living, and smile while he does it.

Transform into Divine Dragon and dominate the world!
He is the only Divine Dragon in the sea who founded an underwater Dragon Palace.
With Crawfish Soldiers and Crab Generals as his followers, wild sharks and gigantic octopuses as his subordinates, he is the dragon that rules the city.

- Description from Novelupdates