Fire and Water, Water and Fire

Heading south from Mossdeep City, I headed down toward Sootopolis City, and since my current surf Pokemon, Linoone, can't learn Dive, I had to stop and catch something that could learn Dive and I caught a Tentacruel, which thankfully can also learn Waterfall.

It's hard to disagree when nothing on your team 

can swim 

Anyway, on our new Jellyfish-o'-Death, we dive deep below the waters surface to reach Sootoplis City! 

After meeting Wallace, we head to the back of the crater the city is built in and reach the Cave of Origin! 

Before I can enter, however, Steven, Wallace, Archie, Maxie, Tabitha, and the cast of Avengers: Endgame all arrive to put their two cents in before I go and save the world. Which wouldn't be necessary if someone hadn't tried to wake up and ancient monster that causes droughts. 

Don't look at me with those puppy dog eyes! 

I head into the ruins, into the deepest, most lava filled part of the tunnel and encounter Groudon!! 

And caught it in the Master Ball with no hassle whatsoever. 

The fish said it best. 

After that, its off to the Sootopolis Gym for the final badge! And after an embarrassingly long time to figure out the Gym's puzzle, we finally reach the Gym Leader! 

He didn't give Manectric or Luxray any trouble at all! Especially since Mightyena took care of his Whiscash. 

With the final badge in hand, its off to Victory Road and the Elite Four!