Alright, i did the ttar nomination for A- rank a while back, but whatever.
(A) -> A-
I havent been using mttar in a long time, though i used him a LOT in the deo metagame.
The most effective set for m-ttar is the dd set, as ttar is one of the bulkiest dragon dance sweepers in the game. It have a nice strong base 164 attack and a decent 71 speed, which with a beneficial nature is just enough to outspeed the entire non-scarfed meta at plus 1 (with the exception of mega-man, mega-aero and mega-zam) and the entire meta at plus 2 (with the exception of sand rush exca). Tyranitars bulk is also insane, with base 100/150/(pseudo)189 defenses, which makes it able to live all neutral STAB and (x2) Non-STAB SE moves and a really nice portions of SE stab moves, almost garanteing it to get a +1/+1, unlike most other sweepers. Tyranitar also gets tons of setup oppotunitues on some common pokemon, such as Latis, talonflame etc.
in itself mega ttar is a really strong, bulky and decently fast dd sweeper which are all great tools to make it function. However TTar have slight 4mss, in what stab move it should be using (crunch or stone egde) which hit very different targets and determinds which checks and counters he struggles the most against. But the 4mss syndrom is not what really stops it from being an effective sweeper. IMO the current meta is just really hash to ttar, with the great amount of sand offence adding a huge opportunity cost in not being able to use a smooth rock ttar as a sand setter, plus his poor match up against sand. It also have a bad match up against the rising amount of choice scarf users in the meta, such as garchomp, landorus, terrakion etc. as well as a lot of common pokemon who can tank a hit and kill it (or just beat it 1v1), such as Keldeo, ferrothorn, slowbro (stone edge variant), mega heracross (crunch variant) etc. Not only that, but it is also weak to the common priority moves, mach punch and bullet punch, making it even easier to revenge.
Mega ttar (compared to the current meta and other options)
Pros:
-Bulky and can set up on a lot of mons
-High attack, making it a great nuke or late game cleaner
-Good coverage options, including: stone egde, crunch, earthquake, ice punch, thunder punch, fire punch, super power
Cons:
-Weak to a lot of metagame trends (balanced team, fighting types, sand, volt turn, intimidate, scarfs)
-Cant be used alongside exca very well
-Competes with a lot of (better?) pokemon for the mega slot
-Outspeed by, and weak to, many scarfed pokemon
-weak to common types (water, ground, fighting, bug and steel)