I finished another single-Pokemon playthrough, this time being one of Heartgold using only a Magcargo named Smogson :3

Something I actually didn't know until recently is that in Heartgold and Soulsilver, you can get three gift Pokemon eggs from Primo in the Pokemon Center in Violet City, and there are codes determined by your trainer ID that you can use to get them, and one of the Pokemon you can get this way is Slugma. I've never really used Slugma before (it's one of those Johto Pokemon that can only be found in Kanto for some reason), so I thought it would be neat to do a single-Pokemon playthrough using one of them.

As for how the playthrough went, it was a bit of a mixed bag, since right at the start it took a little bit to really get going due to Slugma's first attacking move being Smog (which is where the name Smogson came from, I also decided to keep Smog for the rest of the game to go along with it :3), but then once I had a couple moves to work with, it wasn't too bad up until I got to Pryce. I didn't end up healing before fighting him since I thought it wouldn't be too difficult to beat him, but that proved to be a mistake since I didn't have any more Ancient Power PP, and it was the only move I had that could really do damage to his Dewgong, so I ended up trying and failing to beat him by wasting all of the rest of my PP and using struggle because it kept spamming Rest, and I eventually had to bite the bullet and use an ether (which I intentionally never use until the league due to how finite of a resource they are in every game) to beat it with Ancient Power. I was also stuck on Clair's gym for a couple of days, first because I couldn't beat any of the gym trainers' Seadras and then because I couldn't beat Clair's Kingdra because it kept using Hydro Pump, so I ended up having to grind about a dozen levels to beat them all, most of which were actually rare candies, including the three rare candies you get for hitting specific goals at the Pokeathalon. Like the gift eggs, I never knew until this playthrough that you can get rare candies by talking to NPCs at the Pokeathalon after hitting a specific number of jumps, dashes, and tackles, so I thought it would be fun to get all three and use them to help me beat Clair, and that's what I did. After beating her, it also took me a few attempts to beat Kimono Girl Kuni's Vaporeon because Smogson kept getting knocked out by Surf (he can't handle water type moves as you can probably tell), but I didn't have too much trouble after that.