Unfortunately, gaining life for Infusion is not trivial, but the payoff here makes it worth jumping through some small hoops to get there
Nikara is a 2/2 with menace for three mana that lets you draw a card and lose one life if a creature with at least one counter on it under your control leaves the battlefield, Yannik, meanwhile, provides a means of triggering this effect
Cards like Ghostway or Eerie Interlude are examples of blink cards that ramp this defense up to the next level, each being capable of turning a board wipe like Supreme Verdict against the rest of the table, regardless of who cast it
Swan Song is another crowd-pleaser that many blue control players love to use, and the same goes for the Shroud enabler Lightning Greaves
Two mana for a generic tutor at sorcery speed is great, and the creature sacrifice cost can be made into an upside in the right decks