#3 WWE RAW star Erik
As long as Ivar does not return to the mix from injury, Erik will only be cast in cameos on RAW Underground, or in unimportant matches in the WWE RAW brand (or SmackDown, depending on where he eventually ends up). Having him become a part of RETRIBUTION would lend a degree of credibility to the former WWE RAW Tag Team Champion and with all due respect to him, allow him to break out of the stifling and myopic 'Viking' gimmick, that has honestly created a ceiling for the talented man.
Erik certainly looks the part and could be a formidable ally to T-Bar, Mace, Slapjack, and the rest of the faction, lending his services to the collective to wreak chaos and havoc on WWE RAW, until they run into a roadblock in the form of The Hurt Business or the Samoan faction, that Roman Reigns is supposedly putting together over the coming weeks. For him to be forgotten after his partner was injured is cause enough for him to seek RETRIBUTION.