Okies so - let's say you try for it.
Farseer
+jetbike
+singing spear
+runes of witnessing (cause you really don't want to fail one of your Death Mission top-up rolls...)
+shard of anaris replacing his pistol
= 175pts
10, 10, 3/5, 4, 3, 10, 3, 10, 3+/4++
Fearless, Rampage
+2S, 5A on the charge, Rending, Fleshbane, Instant Death in melee (or just S3, Fleshbane, Armourbane, 3A for 40pts less)
12" S9 Fleshbane or shurideath shooting
The Trolltarch mentioned above -
Autarch
+jetbike
+lance
+mantle
= 135pts
6, 6, 3, 4, 3, 6, 3, 10, 3+/4++
5A, S6, AP3, Lance on the charge only, S3
AP- after that
For 40 points more, the Deathseer sounds like a lot more fun... Sure he might explode, but where's the fun if you won't take the risk?

Take the Gem instead of the Shard and save 15 points, take it as well if it gets
FAQ'd like that and spent 40 more...
Makes him the cheapest, fastest, most powerful Phoenix Lord...
Make sure you've got a good Jetbike unit for him to play with if you don't get
DM and he's still going to be a force to be reckoned with...