Almost every single LoR Darkin is weaker than Rhaast when it comes to assimilating it's host with. Starting from the fact that the only way they wake up is in the hypothetical that Aatrox calls them for battle, every single one of them take more turns (represented by they mana cost) to actually be summoned as the Darkin instead of just being a weapon anyone can yield. Aside from that most of them assimilate very pathetic things, with 4 of them assimilating either non sentient or barely conscious things. From these 4, Baalkux, Ibaaros, and Taarosh can more reasonably explain their extremely high costs as they are being kept in places where there are literally no mortal sentient creature to be their host, but Naganeka is literally a giant balista in an open field yet the best thing she could lure was a chicken?
Only one Darkin can be summoned earlier than Rhaast which is ironically Joraal, and aside for being able to lose the fight against the highly trained shadow assassin, he is not nearly as weak as people make him up to be.
So NickyBoi and Necrit made a tier list together and were talking about Rhaast being the weakest of the Darkin for not being able to overtake Kayn (to paraphrase what Necrit said, if Kayn can fully wield a Darkin weapon and Rhaast can't fully dominate over his body, something is wrong), and I've already seen so many people arguing both sides (I swear this happens every time a lore youtuber talks about Rhaast) so I've decided to use the power of DEMOCRACY to see if we can decide the true reason why Rhaast won't/can't kill his host like the other Darkin and what his actual power level is