With evidence, that Relic is still at Dow3, I'm reactivating Future Factions series. This time I show my wishlist of Tyranids units:
Hive Tyrant - another of my favorite commander units, obviously as a Elite.
Tervigon - probably as a Elite, it can be a unique Elite which can reinforce or even produce Gaunts units.
Carnifex - one of my favorite Tyranid units, a Line walker unit.
Biovore - a Line unit probably, serving as a artilery.
Lictor - a Elite stealth unit, definitely.
Haruspex - a Elite or line unit, it might function as a anti-infantry.
Maleceptor - a Elite unit with probably a psychic AoE ability.
As for Super Units, perhaps a Trygon and Mawloc.
Feel free to discuss.