MTL - Marvel: Start with Level Five Mutants - Chapter 333 Cthulhu-turned-Su Yao (please vote for me)

He holds a god-level sign-in system in his hand, punches the goose factory, and steps on the pig factory. Do you think there is no good game?
First feed you two mouthfuls of tainted milk powder, and then send you the legend of the dragon and the Hearthstone gold cartoon for free.
What? Still not satisfied? League of Kings out-of-print skin, give away!
Satisfied? Tch, this is just the beginning…

- Description from novelbuddy

Check in in front of Shicun Liushen, and get the reward Innate Saint Dao Embryo.

Check in in the False God Realm, and get a bonus cross-border amulet, which can be used to randomly enter other worlds.

Check in at Tianshen Academy, get rewarded with the secret of writing, the speed breaks through the limit of the world, and evolves time.

Check in in Xianyu, and get rewards.

After entering the perfect world, Shi Zhong got the check-in system and became a member of Shi Village.

Since then, the Eight Realms of the Lower Realm, the Three Thousand Dao States, the Nine Heavens and Ten Lands, the Immortal Realm and the Sea of ​​Heaven, etc., have all left footprints of stone bells.

- Description from novelbuddy

Zavier met Cosmic Consciousness after his death. He was satisfied with every system that Cosmic Consciousness exhibited, so he wanted all of them. Surprisingly, the Cosmic Consciousness obliged him.

Zavier was reborn in an isekai full of magic and alchemy. Now, he had many routes to upgrade. Interestingly, to coordinate these systems, Cosmic Consciousness gave him the gift of being able to duplicate himself. He could clone a finite number of himself to manipulate these systems.

Magus, Alchemist, Mesmer, Tamer, Hunter, Vampire, Werewolf, Dragonknight, Necromancer.....

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By the way, it wouldn't appear NTR or some bullshit harem of courtships. MC of course will have harem but not for cliches.

A master assassin transmigrates into an interstellar era.