Plot: People always thought of what was beyond their world they thought what lives were out there in the universe and the humans thought were they truly the only ones in the universe Y/N is proof of that because of the device that he bears on his left wrist which is called the Omnitrix The most powerful device in the universe The device allowed him to transform into many alien lifeforms and even using their abilities that are unique to their species y/n has become a hero to his world but now the world and humanity needs his help y/n goes to Chaldea where he would become the last master it's time for y/n to put into action of the experiences that he had accumulated in his life The only question is can he do it or will y/n fail

Name: Y/N Striker
Hair color: Black
Eye color: Dark blue
Gender: Male
Race: American. Human. Magi.
Age: 18
Vital Status: Alive
Appearance:

Elemental affinities: Fire. Water.

Mystic eyes: None

Number of magic circuits: 156

The Omnitrix: Before Recalibration

Omnitrix: After Recalibration

Combat suit:

Joy: before anyone asked even though if the mysteries of the world are exposed that doesn't mean that the whole summoning system for heroic spirits isn't going to disappear or become unavailable and the reason why the mages keep the mystic world a secret is because well they believe that anyone who didn't had any involvement in the mystics like mage families do didn't deserve to know about it so yeah their elitist assholes and yes gods and monsters still do exist and are still around there is a reverse side but it's mostly used to throw monsters that are believed to be near impossible to kill  so basically it's a prison

Tags:
1. Fate/Grand order x Ben 10
2. Aliens
3. Mythology
4. The Omnitrix
5. Harem
6. Male Reader
7. Blood and gore
8. Romance
9. Fluff and smut
10. Time travel
11. Demon god pillars
12. Machine gods
13. Cosmos in the lost belts
14. Epic of remnant
15. Heroic spirits