For your persian, consider Fury Swipes in all of its glory. Between Technician and STAB, every hit will be at a power of 40, giving you a max power of 200. The only reason I'd suggest it over Return is the capability to break through Substitute. If you don't see substitute all that often, then your Persian's set looks fine the way it is; Return is much more reliable than Fury Swipes.
If you do go for Fury Swipes, King's Rock, Wide Lens, and the Razor Claw you already have on are all good items for it. Wide Lens helps with the obvious inaccuracy, King's Rock gives a compound flinch chance since the attack is multi-hit, as well as giving U-turn a Flinch chance. Finally, the Razor Claw will give every attack an individual critical chance, which easily allows for more damage to be dealt.
Also for Persian: Adamant or Jolly Nature work best with it, unless you're going to have a special attack on the set... Rash boosts special attack, though I think you'd do better to just use the set you have with a different nature. Fake Out + U-turn is a great combo.
Any reason your Hitmonchan has Ice Punch on the set twice? Adamant or Jolly Nature, again, would be ideal for Hitmonchan... Not that Lonely hurts it much, most physical attacks would already be fairly close to a OHKO.
Ninjask's nature -would- cripple it if not for that ability it bears. I've got a couple sets you could use for it:
Ninjask @ Focus Sash / Pinch Berry
Any Nature
-Substitute
-Protect
-Swords Dance
-Baton Pass
This set is horribly susceptible to taunt, but it's gotten the job done for me when I used Ninjask. There are a few ways you can use it.
Protect - Substitute - Protect - Substitute - Protect - Baton Pass. Pass five speed boosts and still be at half health so you can pull it off again later, possibly with a pinch berry later.
Protect - Swords Dance [Focus Sash protection] - Protect - Pass 2 Speed and 2 Attack, but you only get one use.
Ninjask @ Pinch Berry
Impish or Careful Nature
-Substitute
-Swords Dance
-X-Scissor
-Baton Pass
EVs in whichever Defense is boosted by the nature you choose and in attack.
Ninjask has enough speed to survive without training in it, so long as you know not to send it out on something that's used Agility or otherwise boosted speed.
The training should allow you to fairly well take a hit from attacking type [physical or special] while you Swords Dance. Be wary of some of the more powerful attackers, as well as Super Effective attacks.
I'm oddly getting a headache, so that's all I've got for the moment.
