Yellow Skarmory take
Dr. Boom the Geodude.
Named after the Hearthstone card often called "Dr. Balanced", Geodude feels that he is the most "balanced" on your team and seeks to prove his worth. In fact, Geodude believes himself to be so balanced that GameFreak had to deny him Selfdestruct in Gen VI until level 29! As such, he must have Self-Destruct to evolve. In addition, you must also learn and keep Rock Blast ASAP, as Dr. Balanced loves the element of RNG to fuck your opponent over at the right time. Explosion will replace Self-Destruct when you get it, of course.
As Dr. Boom's bots send their bombs at random enemies, your Geodude must also send its Rock Blast at a random enemy (determined by coinflip or random.org or something to that effect) in each Doubles+ battle it participates in, forgoing all other moves.
As a Graveler, it feels empowered to take on any challenge, so have it solo Norman's entire gym, because nothing proves you're balanced like earning the Balance Badge, right? However, it keeps striving for more, and it's up to you if you wish to grant its wish.
To evolve into Golem, it must kill ten trainer Pokemon, as Graveler, with either Self-Destruct or Explosion. If you remain a Graveler, solo three Elite Four Pokemon. If you decide to evolve, solo an Elite Four member ("Elite Four" here includes Steven).