>>58919510Oh
Well then no.
Delta Stream does not help it.
Mega-ing your Clefable means it no longer has its actually good defensive abilities.
It can no longer check setup, and is vulnerable to status, including the status it picked up before mega.
Delta Stream is an ability that makes you survive one more turn. It's good on Mega-Rayquaza, because Delta Stream has similar, more flexible utility to Multiscale. You just aren't oneshotting it the turn it sets up, unless you have a hyper specific answer.
Mega-Clefable still doesn't really have what it takes to be an offensive threat on its own with no ability, so all you have accomplished is sabotaging your own defensive profile, because Clefable's abilities carry it hard. Offensively it is about on par with Magic Guard Life Orb Clefable.
It gains a niche at countering weather, this much is true, but it is now vulnerable to things setting up in its face, or just hitting it with toxic/seed and laughing at it. It can be tailored to deal with weather setters, but now your Clefable doesn't really work for anything else, and is a nearly dead slot, AND a dead mega, against teams not using weather, and not great against the other weathers, since Clefable really fucking needs its moveslots to basically function.
Gale Wings doesn't really help it either, mind. Magic Guard can preserve it in the face of hazards, but Air Slash isn't killing anything off of 135, otherwise unboosted. Bravest Bird this is not.
Really, besides a unique ability, at which point sky's the limit, really, the best ability for it... is either Magic Guard or Unaware. Clefable is made by those abilities. If it lost them, it goes down to wherever the fuck Wigglytuff is these days. Maybe a bit better, pure Fairy on a non-ass body is good. The best way, boring or otherwise, would just be the ability to use both on one set, your mega essentially allowing you to toggle. Arguments for both exist, I don't think it matters too much.