In particular, Terminus is expensive at 6 mana, but it most often costs 1 with top deck manipulation
Mono-White Lifegain really shines when you can get a critical mass of lifegain pieces in play, and these provide that for the lowest cost possible
First, the champion, playing Mono-Black Necro Control: Creatures (7) Lands (23) Spells (30) 4 Nevinyrral's Disk 1 Hymn to Tourach 4 Necropotence 1 Ivory Tower 4 Dark Ritual 4 Drain Life 3 Stupor 2 Mind Warp 3 Contagion 1 Serrated Arrows 2 Demonic Consultation 1 Zuran Orb Sideboard Then, in third place, representing the aggro decks of the format, Brian Hackers Bad Moon Necro: Creatures (19) Lands (21) Spells (20) And then finally carrying on the fine tradition of B/r Necro-decks, Chris Pikula, who actually increased the red presence in the deck with Incinerates and multiple maindeck Shatters (Winter Orb, Howling Mine, Serrated Arrows, even Black Vise, Ivory Tower, and Zuran Orb were worthy targets)
Five mana, net a 4/4 first strike and a tutored for legendary card of any type slotted into your hand