Universal Hope

It started when an alien device did what it did, and stuck itself upon his wrist with secrets that hid. Now he's got superpowers he's no ordinary kid he is...Eren Yeager?! 

The boy who swore to destroy his enemies now holds the most powerful weapon in the universe: the Omnitrix. With the Omnitrix bound to him, Eren finds himself thrust into an entirely new battlefield, one filled with alien conquerors, intergalactic warlords, and threats far beyond the Walls. No longer just a soldier in humanity’s war against Titans, but a long forgotten war spanning in the universe. With the fate of not just humanity, but the entire universe at stake, Eren must decide: Will he become humanity’s greatest hero—or its greatest monster?

The fate of not just the walls, but the entire universe, now rests in his hands. Eren x Harem. 

[World building: Fusion of SEVERAL ben 10 elements into the universe of Attack on titan, maintaining themes, nuance and morals of both worlds]

[Age Progression: Eren starts at 10.]

[Chapter updates: 2X per week]