Source battlemind link

When you cast this spell, if your linked ally uses a mythic path ability against a creature, you can use the same path ability against that creature as if you had it yourself, and your linked ally can likewise use any path abilities you use against a creature (even if that ally isn't mythic). For example, if you're a champion attacking a frost giant using the precision path ability, your linked ally can use your precision ability when she attacks that frost giant. If a path ability requires expending uses of mythic power or any other cost, your linked ally must expend that cost for you to use the ability.