Feral Deathgorger // Dusk Sight
Two mana buys a growth counter on a creature plus a card, and then the spell tucks itself back into the library rather than falling into the graveyard: that shuffle clause is the whole mechanism, because it means the six-drop half is never a dead draw and never truly spent, just deferred. What reads as a cheap value sorcery is the front end of a permanent you cast later, when the same physical card resolves as a 3/5 flier with deathtouch that exiles up to two cards from a single graveyard on the way in. The design logic is the split of jobs across the game's arc. An Omen only works if the cheap spell earns its keep on its own, so the expensive body reads as upside rather than a tax paid up front; here the graveyard exile does the double duty, an entry-triggered answer to recursion and reanimation that you never had to run as a stranded piece of hate. The body is the closer's insurance: five toughness plus flying plus deathtouch makes a blocker that trades up against anything and cannot be profitably attacked into, so a card that opened the game drawing you deeper ends it as an evasive threat opponents cannot afford to ignore. One physical card, two windows, both of them justifying their own draw.

