sooo Nebula...

She's from good o' Johto. Conveniently her rival is Silver too. Silver likes having rivals (and when he was younger, people to be better than and push around).

When/If the two make up and end up being like "oh we're definitely more than friends", it's DestinedRivalsShipping! It's a joke from the actual Pokémon set, Destined Rivals, since it included all of Team Rocket with no sign of Silver. So, a pair of rivals, destined to be.

Howeverrrr Nebula during this time works in Unova! As a teacher!! Y'know who's also a teacher in Unova??? Cheren!! And when they slowly come together, finding comfort in familiarity, it's TreatYouBetterShipping. When Nebula inevitably tells Cheren about Silver (and their rivalry, and her old crush), Cheren's half convinced that she'd totally leave Cheren behind if Silver became relevant (or something?) in her life again. But let's be a 100% honest, Cheren would probably treat her better than Silver, at least considering his past. Oh, and the ship name is a joke about the song titled the same thing:

Choke On Your Words [1/5]

Off The Edge