This is my shot at a ROTJ Luke. I wish there was a rebel luke like this. Let me know what you think!

Luke Skywalker, Rebel Hero
Faction: Rebel
Cost: 55
HP: 130
Def: 21
Atk: +13
Dam: 20

Special Abilities
Unique
Melee Attack
Djem So Style (Whenever this character is hit by a melee attack, make a save of 11.
On a success, this character can make an immediate attack against that attacker)
Mettle (If this character spends 1 Force point to reroll, add +4 to the result)
Twin Attack

Force Powers
Force 2, Renewal 1
Dark Temptation (Force 1: +4 Attack and +20 Damage until the end of this character's
turn. At the end of that turn, make a save of 11; if this save fails, this character
joins the opponent's squad until the end of the skirmish.)
Lightsaber Assault (Force 1, replaces attacks: Make 2 attacks)
Lightsaber Block (Force 1: When hit by a melee attack, this character takes no damage
with a save of 11)
Master Speed ( Force 1: This character can move 6 extra squares on its turn as part
of its move)
Use the Force (Force 3: This character's next attack roll counts as a natural 20)

If you're going toward the dark temptation-y side, that was after the NR was established. BTW, Luke Skywalker, Rebel Hero is already a mini, isn't he?

Needs reworking...at a +13 with Twin and lightsaber assault, there a very very few reason one would ever use Dark Temptation... I can get just as much damage with less of a risk. Too many HP's (especially) and overall does not capture the time frame you were hoping for.

I might drop LS assault, that would make DT a far more tempting option I think.

Anakin champion of Nelvaan has djem so + twin for 49

Like I said, I'm mulling dropping LS assault

OK, after taking on board some criticism and thinking about some new ideas, here's a revised version:

Luke Skywalker, Rebel Hero
Faction: Rebel
Cost: 55
HP: 110
Def: 20
Atk: +13
Dam: 20

Special Abilities
Unique
Melee Attack
Double Attack
Djem So Style (Whenever this character is hit by a melee attack, make a save of 11.
On a success, this character can make an immediate attack against that attacker)
Mettle (If this character spends 1 Force point to reroll, add +4 to the result)
Flurry Attack (Whenever this character scores a critical hit, it can make 1 immediate extra attack)

Force Powers
Force 2, Renewal 1
Dark Temptation (Force 1: +4 Attack and +20 Damage until the end of this character's
turn. At the end of that turn, make a save of 11; if this save fails, this character
joins the opponent's squad until the end of the skirmish.)
Lightsaber Block (Force 1: When hit by a melee attack, this character takes no damage
with a save of 11)
Knight Speed ( Force 1: This character can move 4 extra squares on its turn as part
of its move)
Use the Force (Force 3: This character's next attack roll counts as a natural 20)

What do you think?

Its looking better. However, consider adding LS Deflect as it is a staple ability for Luke.

He was able to do this because he essentially used Dark Temptation to do it...luckily he made his save. It wasn't even a stand and deliver blows kind of fight...Luke essentially ran around the room (presumably gaining Force points) and ran in for the kill once Vader goaded him.

As for the new piece, I would consider dropping Use the Force, it just doesn't fit, could be rather abusable and is counterproductive to DT (which must stay). Flurry could stay. And I agree that it may as well just be Lightsaber Defense as Luke demonstrated both of these in the duel (batting away Lightsaber Throw)

110 is probably about dead on as far as HPs (in relation to other Luke figures) for this time frame.

I'm torn on your switch of Twin for Double. While I think Double is the better choice when considering Djem So, I think you need to at least add Greater Mobile and thus drop Knight Speed.

To further add to the theme, you might need some kind of ability such as Protective (with a MOTF twist?) or something to do with being within 6 of an enemy Vader.

Or perhaps: Take your Father's place at my side: This character is able to spend Emperor Palpatine's Force points and may spend force points and extra time per turn.

Basically something along the lines of making his Dark Temptation save a little easier under the right circumstances, but still quite the gamble in others.