The above comments are all very good and I'd pretty much support all of them. I think there are a couple ways you could go with this team in terms of all-out offense or more of a balance.
If you choose to go with offense, I like mosquiton's suggestion of deo-d > ferrothorn
. This thing will get hazards up for you early, which helps out your whole team. While mosquiton's set is good, I personally like this set better:
This set has the advantage over the other set of always beating other taunt leads through the use of mental herb + taunt, while with the other you have to predict with magic coat and can lose the speed tie vs other deo-d leads. The free moveslot is now given to Twave, which means that you can cripple anything that tries to set up on you, while buying free turns for yourself to stack more hazards! This is a really cool set that should serve your hazard-stacking needs well.
Now that you have hazards, a spinblocker is next. You do have chandelure, but it's both frail and slow, so it won't do a very good job of keeping your hazards on the field. I would suggest using spinblocker Gengar > chandy
, as gengar is by far the best offensive spinblocker in OU. A good set would be:
Substitute + dbond is a very cool combination that allows you to take down most spinners that try to KO gar. Take tentacruel for example: you switch in on the rapid spin, then sub. If it switches, all well and good, free sub, while leftovers mean you barely lose any HP in the process. If it stays in and scalds, just sub down until you're at low HP, then dbond. Scad KOs gar and take tenta with it, meaning your opponent now has no way to spin the hazards! Focus blast can be used in the last slot for coverage, while HP fire hits forretress, scizor, and ferrothorn especially hard.
I like your current thundurus set more than double dance since the extra coverage is nice, and setting up both agility and NP often isn't possible, so I'd stick with that imo.
Starmie is tricky--you somewhat need to choose between bulk and power. One set I've been experimenting with is leftovers starmie with max SpA and a moveset of rapid spin / surf / tbolt / ice beam
. This is a bit of a compromise between the bulky set and the offensive one, since it has the moveset and EVs to hit hard but has lefties to recover damage while it doesn't take LO damage so it won't be worn down as quickly. This set has much greater utility than defensive mie so you should find it useful more of the time. If you feel you're getting worn down to quickly though, the bulky set is probably better (and in that case psyshock > psyshic
The rest of the team looks very solid, so no more comments here! Hope my comments helped, and GL with the team!