If you simply wanted to pose an offensive presence while still maintaining the capacity to Spin, regular Avalugg already achieves this since Body Press + Ice Spinner is lowkey tough for most offense to switch into anyway, while H-Avalugg tries to get fancy with Ice + Dark + Rock/Ground(?) coverage or w/e to try and cover neutral. Avalugg can also fend off most spinblockers decently enough with the exception of physically defensive Sableye, which H-Avalugg also fails to beat. This mon just falls into this awkward segway where it's worse than Avalugg/Cryogonal when it tries to spin and worse than Crabominable when it tries to break, and H-Avalugg simply isn't good enough to combine these two traits into a consistent product because trying to lean into one aspect means it substantially sacrifices the other.
You only need ice dark coverage, what are you tacking rock and ground on for? And no, reglular Avalugg can't beat spinblockers as efficiently as it's completely crippled by Wisp, whereas Tera Dark Avalugg beats rotom and phys def Sableye handily; it even does ~50 to blimp when burned, so it's forced to keep recovering giving you a free turn. No, the mon isn't good per se, but it's certainly at worst on par with all that dogshit in C/C+ and I'd definitely rather use it than bink, swalot, and sliggoo-H fwiw.
252+ Atk Strong Jaw burned Tera Dark Avalugg-Hisui Crunch vs. 252 HP / 252+ Def Drifblim: 244-288 (48.4 - 57.1%) -- 91.8% chance to 2HKO
252+ Atk Strong Jaw Tera Dark Avalugg-Hisui Crunch vs. 248 HP / 252+ Def Sableye: 184-217 (60.7 - 71.6%) -- guaranteed 2HKO
252+ Atk Strong Jaw burned Tera Dark Avalugg-Hisui Crunch vs. 248 HP / 0 Def Rotom: 262-310 (86.4 - 102.3%) -- 18.8% chance to OHKO
40+ Atk Strong Jaw burned Tera Dark Avalugg-Hisui Crunch vs. 248 HP / 0 Def Rotom: 225-265 (74.2 - 87.4%) -- guaranteed 2HKO after Leftovers recovery
40+ Atk Strong Jaw Tera Dark Avalugg-Hisui Crunch vs. 248 HP / 252+ Def Sableye: 156-184 (51.4 - 60.7%) -- guaranteed 2HKO
40+ Atk Strong Jaw burned Tera Dark Avalugg-Hisui Crunch vs. 252 HP / 252+ Def Drifblim: 208-246 (41.2 - 48.8%) -- guaranteed 3HKO
252+ Atk Strong Jaw Tera Dark Avalugg-Hisui Crunch vs. 248 HP / 252+ Def Sableye: 184-217 (60.7 - 71.6%) -- guaranteed 2HKO
252+ Atk Strong Jaw burned Tera Dark Avalugg-Hisui Crunch vs. 248 HP / 0 Def Rotom: 262-310 (86.4 - 102.3%) -- 18.8% chance to OHKO
40+ Atk Strong Jaw burned Tera Dark Avalugg-Hisui Crunch vs. 248 HP / 0 Def Rotom: 225-265 (74.2 - 87.4%) -- guaranteed 2HKO after Leftovers recovery
40+ Atk Strong Jaw Tera Dark Avalugg-Hisui Crunch vs. 248 HP / 252+ Def Sableye: 156-184 (51.4 - 60.7%) -- guaranteed 2HKO
40+ Atk Strong Jaw burned Tera Dark Avalugg-Hisui Crunch vs. 252 HP / 252+ Def Drifblim: 208-246 (41.2 - 48.8%) -- guaranteed 3HKO
It also has the marginally cool niche of having good dark coverage for any IDBP sets so you're not walled by ghosts