The Level 9 Shaman power Mountain's MightDDI (Dark Sun Campaign Setting) does the following:
Primary Target: One ally
Effect: Your spirit companion disappears. Until the end of your next turn, the primary target assumes the form of mountain’s might. While in this form, the primary target is slowed, gains resist 5 to all damage, and gains a power bonus to melee damage rolls equal to your Intelligence modifier. The primary target can end the effect as a minor action. Make an attack that is a close burst 1 centered on the primary target.
Secondary Target: Each enemy in the burst
Attack: Wisdom vs. Fortitude
Hit: 2d6 + Wisdom modifier damage, and the secondary target falls prone.
Miss: Half damage.
Sustain Minor: The form of mountain’s might persists.
If you spend a minor action to sustain the power, I assume this means you sustain the effect on the ally (slowed, resist 5 all, +int melee damage).
If you sustain does it also allow you to make another close burst 1 centered on the primary target?