Uuugh. Why did I do this. What possible reason could I have had. It's not even a question.
Mega Togekiss...
Si vis pacem...para mortem.
All right, it's an angel. I was sick of its official design as an egg-plane, so this one is more avian and...well, at least it has a more defined shape, than that oblong thing with swirly wings that called itself a Pokemon.
So, I drew some inspiration from seraphim and things like that, with a lot of wings and no legs. Well, this thing has a large pair of angelic-shaped wings with a second pair adjacent to its tail, and two small hands/feet/what-have-you at its breast. I kept the red and blue specks an it's body, but once again they're more definite now. It still keeps the flattish face, but its weird pointy things are more definite ears/horns/etc now, and it still has the trademark red and blue alteration.
Getting down to competitive, I tell you, if you thought Clefable (which has no base stat that exceeds 100) was ugly, then this thing is satanic. Because yep, it has Magic Guard.
Magic Guard! Immunity to status and weather! Immunity to Stealth Rock! And God, it's fat. Togekiss itself is a well rounded Fairy type with a meaty special attack, above average defenses and decent speed. So Mega Togekiss just improves in degree not in kind:
Base form stats: 85/50/95/120/115/80 (ugh)
Mega stats: 85/65/115/140/140/100 (...help me.)
The stat boosts are individually modest and spread across every stat (save HP, of course), but when combined make it a worse demon than fat Mega Latias, with a much better typing and coverage that Latias would kill for. Because, courtesy it's prior existence as a Normal type, it has fantastic elemental coverage: Fire Blast, Aura Sphere (Steel types perish), Air Slash, Ancient Power, Grass Knot, Dazzling Gleam, Tri Attack, Psyshock (bye-bye Poisons), oh, the list goes on! And it has excellent moves like Nasty Plot (oh God why, this thing is EVIL!), Roost (which negates its Rock, Electric and Ice weaknesses), Defog, Baton Pass (EVIL, I tell you!), Encore, Thunder Wave, Tailwind, Toxic, Wish! And because I'm feeling particularly evil today, I'm doing it a service and granting it Moonblast, because why the hell not. Its base form can abuse the SpAtk Drops from Serene Grace too.
The stat increases are nightmarish. 85/115/140 bulk is monstrous, especiallywith an excellent typing that resist Pursuit, made worse by a large base 140 SpAtk (and that's not even accounting for Nasty Plot!) and base 100 Speed, which is great for a fat Pokemon. Why, this thing puts even Mega Gardevoir to shame! Fear it, for it is indeed the worst nightmare.
Not to say it can't be stopped, though. It can't boost its speed in any reliable way (but Tailwind, ugh...), and it is checked or revenged by certain Pokémon depending on its spread. Offensive spreads are stoppable or revengeable by things like Gengar, Mega Metagross, offensive Mega Scizor, and also by things that can take a non-boosted hit and strike back very hard, like Dragalge or Mega Goodra (hi.) Defensive spreads that do not carry Flamethrower or Aura Sphere are again stopped by Fat Mega Scizor, Ferrothorn, Jirachi (another evil thing) and many steel types, as well as Poison types like Mega Goodra (hi) for example, as also other fat fairies, SpDef Heatran and Talonflame, and so on. Depending on its moves, it will always have trouble with some mons. But I'll eat my audit reports if this thing is allowed in OU for any length of time. Set up is too easy, spreading status is too easy, its coverage is too wide, and it is simply too fat.
Ubers, better prepare yourself.