Mega 
Brambleghast
Type:
Grass/
Ghost
Ability: Accumulate - If this Pokémon is a Brambleghast that has Mega Evolved, it bundles together with other Brambleghast and changes form at the end of each full turn it has been on the field, building up to Mega Brambleghast (Tangled Form) over five turns. (SOS clone)
| HP | ATK | DEF | SPA | SPD | SPE |
| Mega Brambleghast-Tumbled | 55 | 115 | 90 (+20) | 90 (+10) | 40 (-30) | 190 (+100) |
| Tangling Form 1 | 55 | 100 (-15) | 110 (+20) | 95 (+5) | 60 (+20) | 160 (-30) |
| Tangling Form 2 | 55 | 85 (-15) | 130 (+20) | 100 (+5) | 80 (+20) | 130 (-30) |
| Tangling Form 3 | 55 | 70 (-15) | 150 (+20) | 105 (+5) | 100 (+20) | 100 (-30) |
| Tangling Form 4 | 55 | 55 (-15) | 170 (+20) | 110 (+5) | 120 (+20) | 70 (-30) |
| Mega Brambleghast-Tangled | 55 | 40 (-15) | 190 (+20) | 115 (+5) | 140 (+20) | 40 (-30) |
[editor's note: i had to redo the table for the quote box you all are welcome for not leaving it unformatted! also this thing is kind of fascinating, what the hell?]
Moves: Heat Wave
Description
The American Wild West is always prominently depicted with their "signature" tumbleweeds rolling on through the backdrop. Like this, they're mostly harmless, even a nice aesthetic - but in reality, tumbleweeds are an invasive species and a massive issue. Tumbleweeds are both highly mobile, and highly likely to get stuck to things, and each other. Lone tumbleweeds are largely unthreatening, but large masses of entangled tumbleweeds filling streets, smothering farms, and carrying wildfires wherever the wind pleases to blow them. Of course, the larger these entanglements amass, the less mobile they become... but at that point it's too late, and you're stuck trying to dismantle the enormous, thorny pile and round up the seeds before it happens again, all while more blow in to exacerbate.
Now imagine if that were haunted, malevolent, and magic.
Mega Brambleghast utilizes Wishiwashi's ability in order to fulfill the true threat it poses - to you and everyone else who desires not to have the life choked out of them by a thorny, seedy, accumulated mass of undead brambles. Wishiwashi was a special case, so Brambleghast doesn't use its ability exactly, at least regarding the enormous BST boost the ability gave it. However, that enables Brambleghast to take some more liberties to achieve its excellent stat boosts another way - minmaxing. Each turn Brambleghast accumulates, its speed drops as it becomes burdened under the mass of increasingly high numbers of other Brambleghasts. However, each additional bramble contributes to a growing fortress of thorns and thistles. As a result, Mega Brambleghast achieves the same level of reward as Wishiwashi in the stats it needs most. In fact, the difference in limitations is also a blessing in disguise, for sticking to such a low HP stat in exchange for even more astronomical defenses furthers Brambleghast's primary gameplan - the one that synergizes with and enables the ability right from the start: Leech Seed.
Despite its respectable attack and underwhelming bulk, Brambleghast has always been best as a SubSeed user. This makes Brambleghast an ideal choice to not only benefit from the ability but also aid in pulling it off in an equal/opposite manner that Wishiwashi does. Wishiwashi revolves around having Wish and Protect to stall out turns, and achieving the late stages gets it quite the hefty HP stat to facilitate its role as a Wish passer with Flip Turn. Brambleghast, meanwhile, stalls out its turns with a combination of Leech Seed and Substitute, whose low HP means that the opulent defense stats it gets at the late stages amplify the effective value it gets out of each point of HP it drains from its victims.
To further this, its attack also shifts into special attack to enable the use of Giga Drain as a proactive option, as well as Heat Wave to ward off any Grass types that would try to block its Leech Seed. Much like Wishiwashi's Whirlpool, Brambleghast also has Infestation to attempt to trap opponents who can't pressure it, making it that much easier to live turns. Pain Split also synergizes very well, and in many cases is one of Brambleghast's best choices for instant damage and instant healing. Spikes are also a fantastic utility option for a mon that's immune to Rapid Spin and enjoys sitting on the field stalling out turns.
However, one move this Ghost type lacks is Wisp, and one it doesn't is Strength Sap. Due to this, I decided to make its defenses skew towards the physical side - even dropping its special defense at its base and first stage. This is to shore up its defense without Wisp, as well as to incentivize special attackers to counter it. Strength Sap could potentially be a bit too much, so having its defenses skewed works to lower its impact and discourage its use over other options like Leech Seed and Pain Split. Brambleghast gets diminishing returns from Strength Sap's heals - which are already lower against special attackers - while receiving no defensive benefit from the attack drop, which is rather antisynergistic with Brambleghast's desire to sit on the field and chip and drain the opponent.
Curse is also super cool on a mon like this, but probably still not good enough considering Mega Brambleghast's pretty significant four move slot syndrome already.
Those chemicals in the water are turning the gosh darned ducks gay! 
Lokix
counter? I've got a 
instead if you want a 
Mega Quaquaval
, as 
, 
Mega Brambleghast
Mega Lokix
Dachsbun, 
Arboliva, and 
Grumpig.
