Credit to formula4speed for posting about Gliscor earlier here, and they have already mentioned many of the things I say below. But like I said above, I built and played this Gliscor before I ever saw their post, so the similarities are purely coincidental.
I had high hopes for Gliscor, which is the only reason I went through the trouble of using up a Razor Fang (which is pretty darn rare in Scarlet & Violet) to make one for this raid. Unfortunately, Gliscor was only marginally successful and so I didn't bother trying to fine tune it.
The strategy is to Lunge at the start to build Tera and get past the reset. Then you Harden a few times, then Swords Dance as much as possible and EQ to win. That's the plan, at least. Reality was a little harsher on me and my impish vampire scorpion/bat.
I never actually succeeded in my solo attempts with Gliscor, even when I had a double-Intimidate NPC team helping me. I think I could probably get this to solo win if I played it a bit more carefully and maybe got a bit more luck, which is why I avoided giving it an outright F grade in solo. In randoms, you'll get a lot more help from other people using Breaking Swipe and friends, so Gliscor fares better on decent random teams. But in either mode, it's just an OK pick.
Gliscor eats Flare Blitzes over and over again, which is why I ran Poison Heal / Toxic Orb to not worry about being crippled with Burn. But those Flare Blitzes hurt like a bitch, and Harden is a slow boosting move -- so Poison Heal just can't keep up with the damage output. I noticed
formula4speed went to Shell Bell for that reason, and if I use Gliscor in the Emboar rerun (not likely), I will try that out. Also there is further room for exploration with Gliscor using Mud-Slap/Sandstorm/Sand Veil evasion hax, and Screech is another decent option.
Like I said, I was really pumped about Gliscor because it appeared to have lots of room to experiment and have fun. But after playing it and getting roasted with Flare Blitzes so much, and having experienced greater success with other mons -- I kinda lost the love for Gliscor and gave up on it.