Ho-oh resists almost all of Tyranitar's weaknesses (Grass, Fighting, Bug, Ground, Steel) and takes pressure off of T-tar to take special hits for the team. It also can switch into Genesect with no fear whatsoever and act as a bulky pivot for the team; it walls Groudon sans Stone Edge and spreads burn throughout the team. A set with Substitute really manhandles opposing stall as well.
In the past, I've run sand numerous times so hopefully I can contribute to the general discussion. I have a set that doesn't seem to be very popular, but no doubt works.
Mamoswine @ Life Orb
Trait: Thick Fat
252 Atk / 4 Sdef / 252 Spe
- Icicle Crash
- Ice Shard
- Stealth Rock
Pretty good utility Pokemon, it can set up rocks against a lot because of the pressure it can put up on the opponent. Ice Shard can revenge Garchomp (not common but it can cause problems if you encounter it) and Rayquaza; Earthquake does a number to pretty much anything that doesn't resist it, except Giratina, but...
252+ Life Orb Mamoswine Earthquake vs. 248/252+Giratina:29.42-34.79%
252+ Life Orb Mamoswine Icicle Crash vs. 248/252+ Giratina:50.09-59.44%
After a couple of rounds of hazards, I'd like to see you survive that. This set works well with Ho-oh to threaten Skarmory; it gets rid of the main obstructions to Ho-oh fairly well, namely Arceus-Rock, Tyranitar, and Giratina.