Maneuverable Charge [General]
Prerequisite: Dex 15+, Dodge, Mobility, Base Speed +10 faster than norm
Benefit: When taking a charge action in combat, you can make a number of turns, each not more than 90 degrees, equal to your Dexterity Modifier. The action still counts as a charge.
Up the Walls [General]
Prerequisite: Dex 19+, Dodge, Mobility, Base Speed +10 faster than norm
Benefit: as Psi Handbook.
I would do it something like that, the prerequisites ensure that low level characters can't get it and make sense for what you are allowing. The speed increase ensures that either barbarian or monk multiclass qualifies, or that it only functions with the aid of a magic item or spell.
Technik