As this card allows any Treasures to be sacrificed at any time in order to produce an impulsive draw effect, when paired with enough Treasures, it can allow for extremely explosive plays
Even so, the odds of pulling Thought Vessel in a deck of 99 (excluding the commander, who goes into the command zone) are slim, so adding Reliquary Tower can increase your odds of having a limitless hand size
Maleficent, Sorceress), while higher-cost (and rarity) options such as The Queen, Wicked and Vain and Magic Mirror provide strong, recurring mid-game draw support
2017-08-25 If you somehow control a Heralds Horn with no chosen creature type, no spells will cost less to cast, not even creature spells with no creature type
It's something you have to build around a little bit, but if you do, you have some really powerful recursion and a really straightforward engine to start getting pretty crazy value from sacrificing off your bigger creatures