Enchantments like Sigardas Splendor, Angelic Accord, and Promise of Tomorrow ensure you never run out of threats
I consider Bloodletter of Aclazotz a damage doubler with upside because there are plenty of ways to bring the pain without combat
So for Brago, King Eternal and decks like that, or guardian infinite combos, or even just to throw into Derevi for value, this is a neat ability
There's no countering, just dealing with the threat
3 Crystal Skull, Isu Spyglass Mana And Card Advantage Ramp that also serves as card advantage is extremely impressive, even if this card requires the deckbuilding cost of filling your mainboard with historic cards
And while most of them arent worth noting, the handful picked out above really are something special