Seeker of Darkness

[Thomas★Zero 19]

Seeker of Darkness
lv 8 DARK
Fiend/Effect
While you control 2 or more DARK Fiend monsters, you can Special Summon this card from your hand. During your Main Phase: you can banish 1 DARK Fiend monster from your GY; target 1 monster your opponent controls, banish the targeted card. You can only activate this effect of "Seeker of Darkness" once per turn. You can only control 1 "Seeker of Darkness".
ATK/2700 DEF/1300

So Seeker of Darkness is  DARK Fiend monster thats design is based around Guardian of Order where it could be summoned off 2 Light monsters where this can be summoned while you control 2 DARK Fiend monsters. In addition this card can also banish DARK Fiend monsters from your grave in order to banish monsters your opponent controls.

In Decks like Archfiend or D/D/D which mainly focus around DARK Fiend monsters you can utilize this card for its effect, as link material or as Rank 8 Xyz Material.

[o_smily from YCM 11]

Hey. Let's go on ahead and fix some PSCT:

If you control 2 or more DARK Fiend monsters, you can Special Summon this card (from your hand). During your Main Phase: You can banish 1 DARK Fiend monster from your GY, then target 1 monster your opponent controls; banish it. You can only activate this effect of "Seeker of Darkness" once per turn. You can only control 1 "Seeker of Darkness".

I would say that the ATK value is too much for this card, considering how you do not need to Tribute any monsters to bring this card out, and should be decreased by some hundreds or so. 2000-2200 is what I would recommend at most. Otherwise, it's a fine side-boss for a DARK Fiend Deck.