Board Thread:General Discussion/@comment-25334258-20160506022245/@comment-24152851-20160516033044

From AF onwards, Ben seems to think up a name as soon as he sees the alien, probably from the Omnitrix hologram or while he's transforming. With the exception of Brainstorm, and I think Lodestar.

Omniverse changed it back so he has to experience the alien before thinking up a name. As he doesn't name Bloxx and Gravattack in their debut episodes.