Archon of Cruelty By way of being one of the best ETB effects on black cards, Archon of Cruelty has made a name for itself as one of the best creatures you can cheat into play, whether thats with Reanimate, Sneak Attack, or Indomitable Creativity
it was good and playable
The best way to mitigate the card disadvantage is to incorporate cards that can provide value from the graveyard, like cards with flashback or jump-start
You can scry and use this to draw
Like most Pokmon cards, the value of Darkrai depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Great Encounters)
It would likely be about 8th on this list (9th if we are putting Jace in as well) but as I said at the start, the ongoing effects are not so directly comparable meaning that rating is more about performance in the cube rather than quality as a bounce card