Where to begin? Well, for starters, if you're gonna run a Nasty Plot set on Thun-T, either go Timid nature, or keep Modest and swap NP for Agility. There are plenty of Sweepers in OU that out speed an unbuffed Thun-T and that usually means a OHKO.
Lucario looks decent, although I find Close Combat/Mach Punch, Earthquake, ExtremeSpeed/Stone Edge, and Swords Dance makes a better set if you use Focus Sash and a Priority move you can get at least one or two Swords Dances and rape.
Starmie would be better off with a Lefties or Choice Scarf + Trick set.
Excadrill looks good, but I recommend Jolly > Adamant in a Choice Band set.
Blissey needs Seismic Toss > Flamethrower, its SAtk stat is abysmal.
Lastly, Espeon has better utility, higher BST, and way more bulk than Xatu, plus has no Stealth Rock weakness. Just a thought.
That's all, hope this helps :)
