Justin

I see Nightborne/Felborne becoming playable. They were most notable being legion aligned Demon hunters throughout the Suramar campaign. A select few were allowed to join Kil'jaeden aboard his flagship as well. Considering how the Alliance handled the Manari Eredar: it's not too farfetched to assume the Felborne will rejoin the Horde in a similar manner..

Water/Dragon is actually a really good typing. You get all the benefits of being a Water and a Dragon type with none of the standard weaknesses. Not being weak to Ice and Electric is HUGE as they're common coverage options, hitting almost every type for Neutral damage, with rare exceptions like Rotom-H. The only 2 things Mega Feralgatr would need are a good ability (I vote Dragon's maw) and a good Dragon type STAB. After that; it becomes a titanic powerhouse after only a single turn of Dragon dance.

To be honest, gaining a type isn't necessarily always a good thing. In Clefable's case, pure fairy typing lets it switch in on many attacks, with poison/steel being somewhat rare attacking types. Gaining flying type will do one and/or two things:

1) While gaining a ground immunity is great: it'll open Clefable up to Boltbeam, which is a notorious combination with tons of SE/Neutral coverage.

2) If Clefable somehow loses Magic guard; it will be another Stealth rock weak mega. Magic guard has been Clefable's claim to fame since D/P/PT days

Finally; I don't expect the addition of a second STAB to do anything for Clefable offensively. Especially when Megas like Sceptile and Ampharos learn the bare minimum like Dragon pulse through move reminder. I don't expect Clefable to suddenly gain cool flying type attacks.

Mega Clefable is the death of Clefable