Rukkatrukk from its event (I think):
Actus and Exitor-Rho from pulls:
Those two are considered good, but I’m still missing Tan Gi’da for full Mech team.
Tankmasha from farming the shop:
Finally Titus from the shopping event.
Titus is the one I wanted since I started playing, he’s incredibly powerful for being able to ressurect if he kills an enemy with his Vengeance.
The shopping event also brought me much closer to obtaining Marneus Calgar, most expensive Ultramarine character. He’s farmable, but the closer the better. I’m now 430/500 shards, which means it’s possible to farm him in a couple of weeks.