What did you mean someone who's denizen hasn't been replaced by yalbadoth or abracadabra man??? Replaced???? What????
Yaldabaoth and Abraxas are special Denizens that seem assigned to specific Players. They’re treated like the ‘strongest and weakest’ Denizens, but I don’t think that’s the case, there’s likely more to it and that’s just what they think actually happens.
Abraxas is not canonically referred to as the Weakest Denizen, BUT Karkat implies he was given a special Denizen, small and weak, a counterpart to Yaldabaoth for not being actually that good. Given they are the two Gnostic Denizens, it only makes sense that Karkat’s Denizen was Abraxas.