Shadow ball gengar

Yes, try dodging one ShB with the zam or he will faint in one shot, possibly before firing a FS. I would also dodge with M2 as much as possible. Don't dodge with the rest unless you have to.

It is cutting it very close- you have underpowered Ttars and Groudon so you'll be relying on the first 3 to carry the rest. Mewtwo will be your star, but shadow ball will be painful.

There might be a better chance for sludge bomb- since they all do equal or less damage to all your team members, but it is harder to dodge.

Alakazam has to get off at least one FS to be effectice. After your first Tyranitar all the other pokemon will make you loose time, so you better make sure Mewto gets you well ahead of the curve. I don't think you will be able to do it. Both your second and your third Tyranitar should ve powered up at least to the next Breakpoint for Bite (lvl 28 or something). Replace Groudon with something doing effective or SE damage. That will probably be better.