I'm just going to copy-paste a Guard Share set I posted in the old thread:
Two things - one, Life Orb > Leftovers, since you don't really want to take too many hits anyway. Two, Jolly nature on Alakazam? No.
I have no idea why I put jolly... I meant Modest. Musta been the sleep deprivation talking.
But I figured leftovers would be good to recover from Sub, but then I just remembered, Magic Guard = No Life Orb damage! I completely forgot that...
Edit:
I really don't see Alakazam running many sets other than straight attacking sets. Its awful defenses and typing mean it is likely not even going to benefit much from even Magic Guard (aside from using a Focus Sash set).
Supporting is possible with access to Encore and ThunderWave. Screening is possible, but there are better Pokemon to do that. I could see it running a gimmicky set with Guard Share though. It'd be a long shot, but it could definitely mess up some of the walls you might come up against.
Alolkazam@Leftovers/Life Orb/Focus Sash
Ability: Magic Guard
EVs: 252 HP/ 252 Spe/ 4 SpAtk
IVs: 0 Def/SpDef
Natures: Hasty(+Spe/-Def), Mild(+SpAtk/-Def), Naive(+Spe/-SpDef), Rash(+SpAtk/-SpDef)
~ Guard Share
~ Recover/Substitute/Encore
~ Focus Blast/Substitute/Encore
~ Psycho Shock/Psychic(I don't know why you'd want to, but just for the halibut)
Now, the lower your defenses, the better. With Guard Share, you're taking both of the defense and averaging them. Kinda like Pain Split, but with stats. So even though your defense will be lower, your enemy will be suffering as well. I feel like this could really hurt a lot of walls, especially Physical Walls, because Alakazam has TERRIBLE defense. Lets do some simple math.
With a defense lowering nature, and no EV/IV investment, Zam can reach a horrendous 85 Def. Now, Max Def Skarmory can get 416 Def, with 252 Defense EVs and a defense increasing Nature. Combine the two, and you'll be looking at Skarmory with only 250.5 Def. Even more than that, your Zam will ALSO be sporting that 250.5 Def. Good trade, if you ask me.
The only trouble lies with Alakazam having decent SpDef. But with Psycho Shock you'll be hitting them on the lower side anyways. Focus Blast takes care of the pesky Dark/Steel types that irk you, but if you are don't think it's really worth it, you could opt for another move. Any of the extra moves I listed have some type of use on this set, so it's hard to really pick one to go with it. Personally I'd go Guard Share/Sub/Encore/Psycho Shock. But Recover could be useful since your Alakazam might get some decent defenses.
Leftovers is the item of choice, letting you regain the Hp you lose from Subbing, or any attacks you might take with your bolstered defenses. Life Orb is an excellent choice as well, as it obviously lets you hit harder, and with Magic Guard, you don't lose your HP. Focus Sash doesn't really fit the set, but at least secures you one switch in or Guard Share, if you're iffy.
It may come off as a gimmick set, but I could really see this working. Not many people go around Taunting Zam. With his defense, everyone just says "LolOHKO". The main problem I see would be Mischievous Heart users. But then again, they screw with basically everyone.
Also, this Zam loves Sandstorm/Hazards. I can see some switches especially with Encore on this set.