Lets look at the other two HQ units first. The Farseer is a psycher whose primary duty is making the units around him better. The Avatar, is a close combat Monsterous creature. The Autarch, is like a one man version of the Eldar army, flexible and can be equipped to do just about anything.
I had to make one, not so much to use because the other two HQ are already awesome. More of a figurehead for my army. Going though my spare minis I had an extra version of almost all the 2nd editon exarchs. This would guide some of my choices.
First choice was if I should equip him with any of the movement options. I was pretty limited, not having an extra Jetbike or Warp-spider jump pack, but I did have a a set of Exarch swooping hawk wings. Giving him the ability to move about the field fast is key. Knowing my dice I didn't want to risk an HQ with that extra Warp-spider jump. The Jet bike would have opened up more weapon options, but I only have one unit of Jetbikes so he could only hideout in one unit. With the wings, I get the benefit of making him jump infantry, and hiding him in just about any unit, or in a transport if I wanted.
Second Choice was Ranged Weapons...Which lead to the question what did I want him to do? I figured I would make him a one man Tank / Monsterous creature / independant character hunter. The Fusion Gun was the only choice...Str8 AP1 Assault 1 Melta. The 6 WS means he will rarely miss, the AP1 melta means anything he hits that has an Armor value will most likely be toast. Characters will be insta killed unless they have a Toughness of 5+.
Finally was his close combat setup. I could put either a Banshee mask or Maniblasters on him, Where his Init was already one of the highest in the game...why take the mask? The Mandiblaster would give him an extra attack. Next up power weapon or scorpion sword? The +1 strength given by the scorp sword would be nice given his S3...But I much rather take dice out of my opponents hands. The power weapon that you don't get an armor save against is much more valuable.
So how to model this guy. It took me an old Dark Reaper exarch, an old Swooping Hawk exarch and a Fusion Gun from the very old guardian box.
This mod was not too tough...
1) Cut the heads off both exarchs and swap them. Be careful not to rough up the skull necklace on the Reaper body when doing this, as the reaper will be the body of the Autarch.
2) Cut the Shuriken Pistol off the Reaper Exarch at the just above the fist.
3) (Toughest part) Cut the shuriken pistol in half lenghtwise right down the "barrel" from top to bottom leaving a right and left half.
4) Attach the Swooping hawk head to the Reaper body.
5) Attach the halfs of the shuriken pistol to the sides of the hawks head (Mandiblasters)
6) Attach Wings, you will have to bend these out a bit to get around the hawk helmet, but it looks much better with them bent back.
7) Attach Fusion gun.
The finished product...
Painting this guy up was fun. The "Power weapon" is one of the old Web of skulls. Which was an awesome weapon in it's day...however it is no longer available to the Eldar. So this was my 1st attempt at painting a glowing effect on a mini. The "Green" glow I drybrushed down the chains of the weapon, onto the helmet...not quite what I was shooting for...but I learned a bit to try this in again the future.
I actually used this guy in one fight and was pretty pleased with how he did. Jumped out of a unit and popped a Nurgle Dreadie...then hopped over and tied up a swarm of nurgle marines for a few turns before croakin. This was all by himself, leaving the rest of my army to run amuck. Paid for himself in that fight.