The idea behind this is to try and take advantage of lists with either 1 expensive centerpiece ship with support or 2 expensive ships. Most of these ships have some significant arc-dodging capability, so even if a list has great firepower, it often can't bring it to bear very effectively.
These are the bones of the list:
Howlrunner 18
3x AP 36
Rexler Brath 37, VI 1, Ion Pulse Missiles 3, Munitions Failsafe 1 = 42
That's 96 points, leaving 4 points to upgrade Howlrunner or the APs.
Strategy: Brath at PS10 can get an early lock on almost everyone and fire off Ion Pulse Missiles. He picks the ship that will be the biggest problem and fires the IPM. If the the roll is lousy, you just keep the TL, let the missile miss and fire again next round with a Focus. Munitions Failsafe lets you play fast and loose with the IPM, taking shots you would normally wouldn't risk. On the second turn of engagement, one AP (or maybe Howlrunner) rushes in to block if useful, and everybody else sets up range 1 shots. One good round of fire from short range TIEs plus a Defender should do a ton of damage, making finishing off the big ship easier.
Against something like a Phantom, even cloaked, it has a good chance of being dead in a turn.
For the sake of argument, with Focus and Howl Re-Rolls, let's say the APs get a 2, 3, and 3 on their damage results, Howl gets 2, and Rex gets 3.
With 5 defense rolls:
AGI 0 takes 13 damage:
AGI 1 blocks about 2 damage and takes 11 damage (Fat Han takes more like 9, TIE/ln blocks to take away Boost/Evade, and 3PO soaks 5/8 more hits)
AGI 2 blocks about 4 damage and takes 9
AGI 3 blocks about 6 damage and takes 7
These are optimal scenarios, of course, sometimes an AP will die, sometimes Focus tokens will be spent in defense (on both sides), reducing the damage.
With this in mind, what do you do with the remaining 4 points? I think Rex is good as is. Howl could use some defenses. Hull upgrade with Determination is a classic, PTL could also be good. You could also pump up the TIEs. Backstabber is a favorite of mine, and would add some extra punch.
Interestingly, this list could pretty easily swap Rex out for Vader and do more or less the same thing, plus Vader stuff. It's probably a better list overall with Vader, as he hits just as hard as Rex, with great PS, for cheaper, but until the Raider comes out, he doesn't do the damage.
For the sake of argument, though:
Vader (29), Title (0), ATC (1), Ion Pulse Missiles (3), Munitions Failsafe (1) = 34
That saves you 8 points over the Rex build, which can be put into a whole other AP or an EPT for Vader and some more upgrades for the TIE/lns. Maybe you don't need Munitions Failsafe because he can double up TL/Focus first turn.
So either:
Vader, Title, ATC, IPM, Munitions Failsafe/VI = 34
4x AP = 48
Howlrunner = 18
100
or
Vader, VI, Title, ATC, IPM, Munitions Failsafe = 35
Howlrunner, Hull, Determination = 22
Backstabber 16
Obsidian Squadron Pilot 13
Obsidian Squadron Pilot 13
99