I got some ideas:
Underdogs: Win a match with 6 first stage Pokemon (ones that don't evolve don't count, so basically LC mons plus the ones they banned)
Doink!: Reflect each of the following at least once with Magic Coat/Bounce: Will-o-Wisp, Toxic, Thunder Wave, Spore, Stealth Rock, Leech Seed, Spikes, and Sticky Web.
FEAR Itself: Knock out an opposing Pokemon with a level 1 Pokemon 5 times.
Last Stand: Win with your last Pokemon knocking out at least 3 opponents (in a 6v6 game).
Magnet Buster: Knock out an opposing Pokemon that has Magnet Pull with a Steel type Pokemon.
Not in Vain: Knock out an opposing Pokemon with Struggle. (inspired by a silly battle I spectated where this happened)
Hanging On the Hard Way: While starting at full HP, survive an attack with 1 HP without using Focus Sash or Sturdy.
What Type Advantage?: Knock out an opposing Pokemon that could have a 4x effective STAB attack against you. (for example, Garchomp KO'ing a Mamoswine)
Soft Reset: Remove the stat boosts of an opposing Pokemon that has accumulated 4 or more stat increases. (could be +4 in one stat, +2 in two different stats, etc.)
Hard Reset: The same as Soft Reset, but with 8 or more stat increases instead.
Cheap Shot: Score a critical hit while at -6 in that offensive stat.
A Taste of Your Own Medicine: Force a Jirachi or Togekiss to flinch, without using Fake Out.