My Hero Academia: The Rise of Ben 10, Book 3

It's time to go to SPAAAAACE!!!

After getting through his Provisional License Exams, Ben is having a hard time deciding between the Hero Agencies he wants to choose for his first assignment as a Side Kick. With offers from Ryukyu, Endeavor and Mirko Agency, Ben is not short of choices in spite of half the world's hatred of him due to Will Harangue's bad press, but Ben is still having a hard time finding the ideal boss he can learn from. However, he will have plenty of time to decide before that happens, as he and Class 1A are going on a fieldtrip.. and it is the fieldtrip to exceed ALL fieldtrips, as they're going to SPACE.

In his first major stint as a UA Teacher, Tetrax takes the entire class and a few teachers on an all expenses paid trip across the Universe to learn from and visit various Super Heroes from other planets, and the final stop? The remains of Tetrax's old homeworld, in the hope that Chromastone, the only Crystalsapien left in existence, can revive it to its former glory.

However, the trip isn't all that easy, for there's somebody else besides Vilgax pursuing the Omnitrix, and as he leads the League of Villains into the vast void of space, he won't hesitate to use any means at his disposal to wrench the Omnitrix from Ben's cold dying hands.