Ok first of all. Tyranitar is actuallly really good. I'm not even sure why people give him Negative Feedback, he's good. And another thing, Greevil is rather easy, he only has Shadows but here are some movesets I like for Tyranitar:
Tyraniboah
Crunch
Thunderbolt/Ice Beam
Focus Punch
Substitue
Tyraniboah is a big threat in the OverUsed(OU) Metagame. In XD, this set is pretty good. If you didnt get the Birds, Thunderbolt will rip through Moltres and Articuno, but not enough to OHKO them. Crunch is for STAB, plus it has good overall power. Focus Punch is great, if you can predict he will switch. Sub is for if they attack your T-Tar you might be able to give them a Focus Punch. Ice Beam is a choice, it depends on your team, if you have someone already with Ice Beam, then stick with Thunderbolt, if you have someone with Thunderbolt already, take Ice Beam. Ice Beam also rips through Dragon,Flying and Grass types.
Dragon Dance Tyranitar:
Dragon Dance
Rock Slide
Earthquake
Taunt/Substitue/Aerial Ace
This is a pretty good version of Tyranitar. Once you get about 2 Dragon Dances in, its a pretty much good game. Rock Slide for STAB, plus it hurts Salamence, Earthquake devastates pretty much every Pokemon except Pokemon with Levitate, or Flying Pokemon. Taunt isint really neccisary in XD, since almost nobody uses Stat-Ups. Sub is a good choice, since you can DD while a Sub is up. Aerial Ace is a pretty weak move, but it does hurt Grass types, but i reccomend Sub insted.
Choice Band Tyranitar:
Rock Slide
Earthquake
Focus Punch
Body Slam/Aerial Ace
Choice Band is a pretty nice item, but you need to switch a lot. Rock Slide again rips through Flying types. Earthquake with CB is deadly. It can and WILL rip through anything that doesnt have Levitate or Flys. Focus Punch is a predictor, or you can use a Follow Me combo. Aerial Ace is for Grassers. Body Slam is almost a Snorlax kind of thing, but its useful. Plus you can try to get lucky with Para.
And that is all the T-Tar sets for now. I hope this can help you lol
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