don't worry too much about the last part, just be aware that tyranitar is extremely strong here, and only partially for the same reasons as in mainline
most shinies were changed
the charmander line, for example, has mega charizard x's color scheme (except mega charizard x itself, which has y's color scheme instead, it's exactly as confusing as it sounds)
any random pokémon you have no plans of using, like one of the however many meowth the game wants to hand out
on that note, do you want to skip the middle man and get a kingdra?
funny story
you can actually trade in this starry area
and i actually have a flygon from wonder trading there
that aside, togepi should be available in a house in lapis by now