I'm a Hunter multiclass Seeker, Paragon Multiclassing paragon path.
I have a Seeker encounter power called Winter Spirit from my paragon path that has a Special entry that reads:
You can use this power as a ranged basic attack.
I also have Rapid Shot from Hunter which has an Effect entry that reads:
You make a ranged basic attack with a weapon against each creature in or adjacent to a square within the attack's range. You take a -2 penalty to the attack rolls.
If I use Winter Spirit with Rapid Shot can I use it with each attack I make? Or just one and the rest are regular RBA's? Or could I use Winter Spirit with one attack and use other powers useable in lieu of a RBA for the rest?