Summon: Ixion

The design idea is temporary exile priced into a body that actually wants to attack. Chapter I is an Aerospark effect: it removes an opposing creature only while the Saga survives, which turns the whole card into a wager against its own clock. Because the third lore counter arrives after the draw step of the Saga's third turn and the sacrifice resolves immediately, the exiled creature returns after two full turn cycles rather than permanently. Chapters II and III are the concession to that return: +1/+1 counters on up to two of your creatures plus a little lifegain, so the payoff drifts from denial toward board development as the timer runs out. The 3/3 first striker holding the enchantment up means this never plays like a static Oblivion Ring; the lore-counter turns are also combat steps you spend swinging while the removal does its work, so the card stays active during the window it polices. The catch is the one every temporary-exile enchantment carries, sharpened by the Saga's fixed lifespan: any early answer (bounce, a sacrifice effect, a board wipe) hands the exiled creature back ahead of schedule, and the body and the exile leave together, since both live and die with the same permanent. The window is only ever as durable as the Saga itself, and unlike most exile effects, this one is guaranteed to expire on its own even if nobody touches it.