Let's do this. Suggestions/things to try and in bold.
Will add sprites tomorrow, sorry if this bores you.
- Replace Night Daze with Dark Pulse. Yes, the Accuracy-lowering chance and slightly higher power is nice, but Dark Pulse has a flinch chance and has a 100% accuracy STAB move. After a Nasty Plot, any STAB attack from Zoroark is going to wreck everything in it's path. The slight power drop in Dark Pulse won't matter much at all.
- Life Orb instead of Expert Belt. Zoroark's moves don't provide enough coverage to it to make an Expert Belt a good option. Since Zoroark is frail, it doesn't care too much about the 10% HP drop when attacking, and you get that 30% power boost with every attack.
You could also try a Choice Scarf set, as your team lacks one. If you do so, replace Nasty Plot with Trick. Screw up a wall and give another Pokemon like Claydol or Cofagrigus a chance to set up. The Scarf works very well on Zoroark, as it trolls people who think they can revenge kill the Pokemon that Zoroark hides itself with.
Good, except you could try an EV spread that give you a bit more bulk.
Calm Mind and Nasty Plot + Trick Room sets are very similar to each other; a Nasty Plot + Trick Room set is another thing you could try out. If you want to try it out, replace Calm Mind and Pain Split with Trick Room and Nasty Plot.
Good, consider Adamant though. 105 Speed is pretty good as it is, and 125 Attack especially appreciates the raw power Adamant gives it.
- Replace it with Blastoise. Claydol has a unfortunate Psychic typing which only gives it more weaknesses and resistances it can't make good use of, while the Ground side of it leaves it and Flygon fully exposed to Ice without a single reliable resistance in the team. For that reason, Blastoise will become your spinner. I use this set:
>Blastoise @ Leftovers
EVs: 252 HP, 252 Def, 4 SDef
- Aqua Jet
- Rapid Spin
Spins hazards, Roars things out, spreads burns and catches the opponent off-guard with a surprising priority attack in Aqua Jet.
Slowbro and Rhyperior are also good choices, with the former having higher bulk than Blastoise, and the latter having a very good Attack stat and access to Rocks, although both forfeit Rapid Spin, but that isn't as much of a problem with this team due to it having no Rock weaknesses.
I almost never see Pory, glad to see it in use. <3
- Replace Nasty Plot with Hidden Power Fighting/Dark Pulse. Porygon-Z is too frail to make good use out of Nasty Plot, and with it's Normal typing that gets no coverage at all it rarely gets a chance to switch in and set up. Hidden Power Fighting is excellent coverage, although it leaves you exposed to Ghosts like Cofagrigus and Mismagius, although they can be removed with Dark Pulse.
- Outrage is generally better than Dragon Claw. More power, and with Dragon attacks going almost unresisted, being locked in isn't much of a problem.
U-Turn is also a decent move that you can replace for Fire Punch or Stone Edge.
They are just my ideas of what would improve this team. If you don't like them, fair enough.
Good luck with your team. :)