Here is a working list for HH 3rd Legion.
LOW:
Fulgrim with Fireblade
ROW Mura Skara
HQ:
Eidolon
Legion Champion
AA
Melta Bomb
Refractor Field
MC EC Relic Blade (I forgot the name off hand)
Sonic Shrieker
Primus Medicae
AA
Refractor Field
Melta Bomb
Power Sword
Sonic Shrieker
Void Shield
Command Squad
+2 Chosen
Melta Bomb
3 Power Swords
2 lightning claws
Troops:
Tactical Legion Squad
+10 Marines
Legion Vexilla
XCW
AA
Phoenix Spear
Melta Bomb
Tactical Legion Squad
+10 Marines
Legion Vexilla
XCW
AA
Phoenix Spear
Melta Bomb
Legion Support Squad
Plasma Gun
Elite:
Palatine Blade
+2 Blades
Sonic Shrieker
Contemptor Talon
+1 Contemptor
2 Assault Cannon
Fast Attack
Dreadclaw
Dreadclaw
2 Javelin Land Speeder
Heavy:
Predator squad
+1 Predator
lascannons on both tanks
Eildolon, the champion, and the Medicae Primus run in the with the blades in a Dreadclaw. The Void Shield will protect them from shooting once they have disengaged from the first combat (by the nature of the dreadclaw being an assault vehicle). Eildolon and the champion will bounce back and forth between challenges depending on whether I get the charge or if I need the champion to tank for me in a challenge due to the EC relic's ability to trade attacks for increasing the invul save. Fulgrim runs with the command squad in the other dreadclaw. The contemptors and the land speeders will outflank due to the ROW. Personally I like the preds compared to the sicarion due to the buff the autocannons got in 30k with 4 shots.