Going in cold for a tourney, gutsy.
As a caveat, ignore all of my suggestions that (1) you don't like and (2) don't fit your own play style.
I assume the archon is gonna chill with the Trueborn -- that single venom is about 250 pts. In other words, the collective cost is more than a stock issue wraith knight but will die to a couple of lascannon shots rather than 9.
The least expensive route (i.e., status quo route)-- Changing the Archon to a hammy with a liquifier gun will save you some points (fine cast archon to fine cast hammy i assume is about the same cost) and give the trueborn feel no pain. Further the blaster born seem out of place with the rest of the army which has range but the blaster born would have to close in to reach that 18" range to be effective. Could reduce the squad size of trueborn and run them with splinter cannons and use the points savings on some vehicle upgrades for the eldar vehicles. Holo-fields (+1 to jink can't go wrong) Shruiken cannons (their fast vehicles so can move and fire two weapons + option other than serpent shield which can be kept for a defensive role while you weaken the opposition).
On a possibly more expensive side--
-Sadly I think you should rethink the DE in the list, right now they are serving a more redundant role rather than a synergistic role. The blaster born could be replaced by by fire dragons and yet another wave serpent. A jetseer with a mantle tossing out buffs to the fire prisms (guide and prescience) and warp spiders and and swooping hawks are strong choices for additional anti infantry fire (with warp spiders adding some anti-air just due to the number of S7 shots they can snapshot).
-DE allies with Baron with Beasts is a solid choice as it adds a rather tough assault element to your force that it is lacking. This would be filling a more synergistic role of providing something your Eldar are lacking. (Although with as much fire power your packing, it might not be needed.)