In the Kanto portion of the game, I decided to clear the Power Plant fiasco and travel to all of the major cities before fighting any Gym Leaders. Having done all that, I stop off at Pewter City for the battle with Brock, going in classic order.
*Battle option is on Set, for future reference.*
First opponent is Graveler, who goes down fairly quick against my Mamoswine's Earthquake.
In his place comes Omastar! I switch into Ampharos, and he uses Brine for only a small amount of damage as result. Between my use of Light Screen on one turn and then Discharge on the next, Brock switches into Rhyhorn.
With an Earthquake coming in, I went into Heracross, who tanks without an issue and defeats Rhyhorn with Close Combat.
Went for CC once again when Brock's ACE Pokemon Onix came out on the field, but it surprisingly TANKED by a sliver of its HP, and nearly defeated Heracross with Rock Slide! Using Reversal on the next turn, Onix was defeated.
Kabutops was up next. I switched in to Gyarados, who took a hit quite well from the incoming Aqua Jet, no doubt meant to take out the last bit Heracross' HP...I had Gyarados use Dragon Dance and Waterfall, and after two consecutive hits, this battle was almost done.
Finally, we come to Omastar, who was already on lower Health...I thought we'd be able to end it with a mere Bite attack from Gyarados, but Brock Used a Full Restore to bring it back to 100%! I had Gyarados use Waterfall, but it wasn't quite enough...! Omastar responds with Ancient Power, which not only lands the finishing blow to Gyarados, but also grants it an all-around boost to its attacks!!
Lord Helix is here...And he's here to SLAY.
And I'm not even kidding. From then on, he legit sweeps the rest of my team. I honestly laughed out loud. And I'm actually happy to see a Gym Leader steal a victory like that. It almost never gets to happen...