The minus ability leaves a bit to be desired, since it will often fail to kill a big creature, but it does have the potential to kill indestructible creatures like Hazoret the Fervent, and it can at least finish something off after a block
Of course, you'll want to make sure Blood Hypnotist is accompanied by cards that generate Blood tokens, so this bloodsucker isn't a great candidate for slipping into the decks you already have
The Phyrexian horror has an Oil Slick version, along with a Step and Compleat foil treatment
Battle Screech Owl Familiar Palace Familiar Raven Familiar Lieutenant Kirtar Budget lands to consider: Seaside Citadel Yavimaya Coast Canopy Vista Prairie Stream Exotic Orchard Port Town Fortified Village Irrigated Farmland Scattered Groves Blighted Woodland Cards to consider cutting: Coat of Arms Illusionist's Bracers Crystal Ball Fable of Wolf and Owl Gravitational Shift Favorable Winds Sphinx's Revelation Explosive Vegetation Wing Shards Cloudfin Raptor Skymark Roc Oketra's Attendant Aerie Mystics Aven Wind Guide Windbrisk Raptor Arctic Aven Sunpetal Grove Glacial Fortress Temple of Enlightenment Temple of Plenty Good luck with your deck
In a long game, hell certainly take over the board if he isnt dealt with
Its fast enough that it can get key threats out underneath your discard spells, at which point theres little you can do to hold them off