Rapid Fire: Once during this character's turn, if the target was just hit by your attack, make an immediate attack at +2 attack against the same character.

Is this in the neighborhood of what you are looking for? I think this is very interesting and a way to weaken Evade. The more Evade rolls you force the Rebels to make, the more likely damage will go through.

Revisions
Change Juno Eclipse, Starkiller's Pilot's Commander Effect from "Allies within 12 squares can choose to be subject to enemy commander effects as well as allied commander effects." to "Allies within 12 squares can choose to be subject to Unique commanders' commander effects."
Change the effects of Wrath of the Dark Side from (Force 7, Replaces turn. Choose 2 adjacent corners on this character's base. Every character within line of sight of both corners take 70 Damage, save 16. When checking for sight, the lines cannot pass through this character's base.) to (Force 6; Replaces turn; Choose 2 adjacent corners of this character's base. Every character within a line of sight of both corners and within 18 squares take 60 damage, save 11, and are considered activated this round, save 16.)
Remove Jedi Hunter Extremist from Lord Palpatine.
Add Jedi Hunter to Lord Palpatine.
Change Lord Palpatine's cost from 129 to 102.
Remove Immediate Droid Reserves 35 from Kazdan Paratus, Eccentric Outcast.
Add Immediate Droid Reserves 30 to Kazdan Paratus, Eccentric Outcast.
Replace Force 3 from Darth Vader, Bane of the Jedi with Force 2.
Replace Lightsaber Throw 5 from Darth Vader, Bane of the Jedi with Lightsaber Throw 4 (Replaces attacks; sight; make 1 attack against one enemy, ignoring cover, and against all characters within 3 squares, with an attack rating of +10 Attack.).
Replace Force Push 3 from Darth Vader's Apprentice with Force Push 1.
Change Darth Vader's Apprentice's cost from 34 to 41.
Remove Quadruple Attack and Twin Attack from Imperial Medic.
Change Imperial Medic's Commander Effect from "Once per turn, trooper followers within 6 squares who hit a non-adjacent enemy can make one immediate attack against the same target with a +2 bonus to attack. This cannot be used on attacks of opportunity or when the follower is combining fire." to "Trooper followers (including this character) within 7 squares gain Rapid Fire (On its turn, if this character hits an enemy, it can make an immediate non-cumulative attack against the same target with a +2 bonus to attack. This ability cannot be used when making attacks of opportunity or combining fire.)"
Add Double Attack and Furious Assault to Imperial Medic.
Replace Rebel Reserves 30 from Bail Organa, Senator with Rebel Reserves 20.
Replace Diplomat from Bail Organa, Senator with Senator (When an enemy attacks this character, they must attempt a save of 11 that cannot be rerolled. If the save is not made, the attack roll counts as a natural 1.)
Remove Force Push 4, Force Push 5, Parry, and Lightsaber Deflect from Kento
Add Lightsaber Defense to Kento.
Remove Impulsive Charging Assault +10 from Wookiee Crusader
Add Impulsive Momentum and Impulsive Charging Fire (When a Unique ally is defeated, this character gains the Charging Fire Special Ability for the rest of the skirmish) to Wookiee Crusader.
Add the phrase "with a Force rating who costs more than 25 points" to Impulsive Force Renewal 2, Impulsive Vicious Attack, and Impulsive Rage from Maris Brood, Felucian Leader.
Replace Force Lightning 7 (Force 7, replaces attacks and next turn. 70 damage to target enemy and all characters adjacent to the target, and 30 damage to each character within 3 squares of the target. The target and adjacent characters can reduce the damage by 40 with a save of 11. The characters within 3 squares can reduce the damage by 20 with a save of 6. All affected characters are considered activated this round, save 11. The damage is dealt on this turn. This character cannot take any actions until after its next turn, including rerolling failed saves, making attacks of opportunity, or being affected by commander effects that modify this character's position on the battle map. This character does not benefit from any Attack, Defense, or Damage bonuses until his next turn. This character cannot take any actions on his next turn, including Force Renewal 2, or any other abilities gained from other effects.) from Darth Desolus with Sith Lightning 6 (Force 6, replaces attacks and next turn. 60 Damage to target enemy and all characters adjacent to the target, and 20 damage to each character within 3 squares of the target. Characters who take 60 damage can reduce the damage to 30 with a save of 11. Characters who take 20 damage can reduce the damage to 10 with a save of 6. The damage is dealt on this turn. This character cannot take any actions until after its next turn, including rerolling failed saves, making attacks of opportunity, or being affected by commander effects that modify this character's position on the battle map. This character does not benefit from any Attack, Defense, or Damage bonuses until his next turn. This character cannot take any actions on his next turn, including Force Renewal 2, or any other abilities gained from other effects.)
Replace Triple Attack from Darth Phobos with Double Attack.
Reword I Sense Your Fear (Force 6, range 4, replaces turn; 2 target living enemies get -4 Defense, and cannot benefit from Attack, Defense, or Damage bonuses while within 6 squares of this character for the rest of the skirmish. Both of these effects can be negated with a save of 16, which cannot be rerolled. Each time the targets move out of 6 squares from this character, they must attempt a save of 11. If the save fails, the effects of this Force Power have the range removed for that character. Each time the affected characters move within 6 squares of this character, they can attempt a save of 16 that cannot be rerolled. On a success, they are no longer affected by this Force Power.) to (Force 6, range 4, replaces turn; 2 target living enemies cannot benefit from Attack, Defense, or Damage bonuses while within 6 squares of this character for the rest of the skirmish. Both of these effects can be negated with a save of 16, which cannot be rerolled. Each time the targets move out of 6 squares from this character, they must attempt a save of 11. If the save fails, the effects of this Force Power have the range removed for that character. Each time the affected characters move within 6 squares of this character, they can attempt a save of 16 that cannot be rerolled. On a success, they are no longer affected by this Force Power.)

Sorry...trying to keep up-to-date with modifications, but I'm in the process of posting a custom thread for darthbane53's comp, maintain my other thread, and regulate my custom comp...I do try, but I can only check the forums between assassinations from Xizor- I mean business trips