Sorry I'm late with this, got distracted with another team and forgot to ladder. I did get a few battles with it over the last few days, though most of this comes from prior experience. Here's the set I ran for most of the testing.
Dragalge @ Black Sludge
Ability: Adaptability
EVs: 200 HP / 252 SpA / 56 Spe
Modest Nature
- Draco Meteor
- Sludge Wave
- Focus Blast
- Toxic Spikes
I feel like Galge is one of those mons that works well against certain teams, but but seems to fall flat against others. It fairs alright against most balance teams, since you can come in pretty easily and fire off some STAB attacks, but thanks to balance being balance there's nearly always some kind of defensive Steel type, which tends to make Dragalge's STABs pretty useless until it gets removed. Running into Mega Metagross, Mega Scizor, or Jirachi can turn this thing into a straight up liability. Against offense, Dragalge dies really quickly for something intended to pivot into resists, and its slow speed means its not going to be outrunning much of anything. Granted, Keldeo's popularity helps it in this matchup, but otherwise Dragalge tends to struggle. Galge's best matchup is against stall, where Toxic Spikes are generally pretty powerful and Galge's slow speed is less of a problem. Solid matchup when it does come up, but it's so rare these days that that's not exactly the best selling point when choosing it for a team.

Dragalge @ Black Sludge
Ability: Adaptability
EVs: 200 HP / 252 SpA / 56 Spe
Modest Nature
- Draco Meteor
- Sludge Wave
- Focus Blast
- Toxic Spikes
I feel like Galge is one of those mons that works well against certain teams, but but seems to fall flat against others. It fairs alright against most balance teams, since you can come in pretty easily and fire off some STAB attacks, but thanks to balance being balance there's nearly always some kind of defensive Steel type, which tends to make Dragalge's STABs pretty useless until it gets removed. Running into Mega Metagross, Mega Scizor, or Jirachi can turn this thing into a straight up liability. Against offense, Dragalge dies really quickly for something intended to pivot into resists, and its slow speed means its not going to be outrunning much of anything. Granted, Keldeo's popularity helps it in this matchup, but otherwise Dragalge tends to struggle. Galge's best matchup is against stall, where Toxic Spikes are generally pretty powerful and Galge's slow speed is less of a problem. Solid matchup when it does come up, but it's so rare these days that that's not exactly the best selling point when choosing it for a team.