Air Balloon
This works a lot of Air Balloon Heatran, meaning it can wall stuff like Garchomp really well. However, Air Balloon Magnezone is only really needed when you have a really big ground weakness on your team, otherwise this item is pointless.
Pros
Gives Magnezone a ground immunity
Makes Magnezone only have two weaknesses (Fighting and Fire)
Allows it to wall ground types pretty well
Cons
Cannot come in on an attack, for fear of breaking the balloon
No recovery
Only one time use
Leftovers
Leftovers, in my opinion, is the best item for Magnezone, because it allows recovery. However, only have Leftovers when you have a ground resist or immunity on your team, as so you don't open up a ground sweep for your opponent.
Pros
Gives it recovery
Can wall stuff better
Cons
Gives it crippling 4x ground weakness
Overall, it mostly depends on how well your team is synergyzed, but if you ask me, I would say Leftovers is the superior item.
