Right. A lot of it is about combining one of the top at-wills with a build that has a nova option to burn off all the standard action encounter powers, leaving just immediates. Do that and you're going to be well on your way.
Swordmage MC Druid as an example:
Initiate of the Old Faith gives Wildshape+Grasping Claws(melee basic) or you can just go WereX for a theme.
At-Will - Magic Stones = attack and mark 3 targets
Encounter - Charm Beast+Wind Wall, eventually Charm Beast+Infiltrating Drone
Daily - Clinging Drone(no shifting next to Fighter for rest of combat is effect!)+Writhing Henge eventually
Utility - lots of choices - Serpent's Cunning for +1 power bonus to Intelligence attacks+free skill+bonuses, Camouflage Cloak for encounter Invisibility, Clear the Chaff for a very strong leader saving throw option.
Take lots of Swordmage interrupt options and then you're set.
Swordmage MC Druid as an example:
Initiate of the Old Faith gives Wildshape+Grasping Claws(melee basic) or you can just go WereX for a theme.
At-Will - Magic Stones = attack and mark 3 targets
Encounter - Charm Beast+Wind Wall, eventually Charm Beast+Infiltrating Drone
Daily - Clinging Drone(no shifting next to Fighter for rest of combat is effect!)+Writhing Henge eventually
Utility - lots of choices - Serpent's Cunning for +1 power bonus to Intelligence attacks+free skill+bonuses, Camouflage Cloak for encounter Invisibility, Clear the Chaff for a very strong leader saving throw option.
Take lots of Swordmage interrupt options and then you're set.