Help with a class idea

[Digitalfruitz]

Hello all! I want to create a class based around size alteration. I plan on it being somewhat similar to the comic book characters Antman and The Atom.

[Grod_The_Giant]

For what system?

[Digitalfruitz]

For what system?

The system would be pathfinder (although if one already existed for 3.x I could convert it)

[Artagon]

I'd probably base it on Rogue, since sneak attack would make a lot of sense for his 'Ant-Strength'. Additionally, he has the stealthy features when he's ant-sized, so that fits too.

I'd say you could add Rogue Talents that allow you to change by one size category per talent selected as a free action. Each category difference changes your movement speed by 5 ft. I'd make increasing and decreasing size be different talents, with decreasing size reducing speed, and vice versa, other size modifiers would also apply. While diminutive they could probably get auto-sneak attack damage. While Colossal I'd give them DR 5/- or so.