Ice Run complete!

And what a finish.

If there's one thing the run crystallized in my mind (lolol) it's that all of my assumptions about the Ice type were pretty much borne out - in this case, that if they don't get hit they can bring down everything in sight.

Let's take a look, shall we? And I'll keep track of one-turn wins here.

Drasna
Oh come on, like I was going anywhere else to start.

Monokuma v Dragalgae
Icicle Crash OHKO. (1)

Asahina v Noivern
Ice Beam OHKO. (2)

Hakagure v Altaria
Ice Punch OHKO. (3)

Byakuya v Druddigon
Ice Beam OHKO. (4)

Siebold
Best of a bad lot for the type, in theory.

Kyoko v Clawitzer
Thunderbolt crits, OHKO. (5)

Hakagure v Barbaracle
Wood Hammer OHKO. (6)

Asahina v Starmie
She opens with Shadow Ball which takes about 3/4 off, Surf's retaliation brings Asahina to 99/174. On the Full Restore, I Draining Kiss 30% off and Shadow Ball finishes.

Byakuya v Gyarados
Thunderbolt OHKO. (7)

Wikstrom
I never actually ended with Malva before, so I figured let's try it... only I forgot to heal beforehand.

Chihiro v Klefki
Because of Prankster, Klefki gets Spikes off before falling to Earthquake. (8)

Asahina v Aegislash
Shadow Ball does 35% and drops Shield Form's SpDef, but Iron Head KOs coming back.

Chihiro v Aegislash
Earthquake finishes the sword off, who would've probably gone for Iron Head again if it wasn't suffering from a severe case of KTFO.

Kyoko v Scizor
Surf does 60%, and a combo of Spikes and Iron Head has Kyoko at 137/260. Second Surf does Scizor in.

Hakagure v Probopass
Brick Break triggered Sturdy, and... remember when I forgot to heal? And how Haka's last move was Wood Hammer? Yeah, Flash Cannon knocked it down to 9 HP. The Snow Warning-induced Hail finishes. (9)

Malva
Of course, we have to finish with Fire.

Chihiro v Pyroar
Earthquake goes first, and it's a OHKO. (10)

Byakuya v Talonflame
Talonflame goes first and Flare Blitzes, which criticals Byakuya to 80/245. Ancient Power does the rest. (11)

Kyoko v Torkoal
Hint: It involved Surf. (12)

Asahina v Chandelure
The opening Shadow Ball... lands critical and OHKOs. (13)

Diantha
There's no way I can keep running this train on the CHAMPION, can I?

Asahina v Hawlucha
Ice Beam OHKOs. (14)

Chihiro v Tyrantrum
Earthquake does about 90%, and Tyrantrum counters with Head Smash which criticals... but Chihiro survives with 42 HP and Tyrantrum goes down to the recoil. (15)

Monokuma v Goodra
Icicle Crash OHKOs. (16)

Hakagure v Aurorus
Hail kicks in, and then a Mega Brick Break does what it usually does. (17)

Monokuma v Gourgeist
Icicle Crash OHKOs again. Five in a row in one turn! (18)

Monokuma v MegaGardevoir
I freaked out a bit when it traced Snow Cloak... forgetting that going Mega switches it to Pixilate anyway. Moonblast takes the Bear of Despair to 71/200... but Shadow Claw does 95%, enough that the hail damage makes Makoto the champ! (19)

Pictured: I got the hoodie, but you can't see the idiot hair.

That's 19 out of 22 Pokemon gone in one turn, the fastest run yet. I don't know HOW I'm going to beat that.