Invasion of Karsus // Refraction Elemental

The front face lands as a board wipe that comes pre-loaded with a threat on the far side: three damage to every creature and planeswalker the moment it enters, then a Siege sitting on the battlefield waiting to flip. The defender you assign cannot attack it, but the battle is a contested object rather than a private one, and both you and other players can chip away at its defense counters. When it is defeated, its controller (you, the caster) exiles and casts the transformed side, no matter who dealt the final point. The battle is a public timer on a private reward.

Refraction Elemental converts spell volume into a table-wide bleed. Every spell you cast arcs two damage at each opponent, so a hand of cheap spells accumulates reach across a whole board without ever committing to an attack. The Ward keyed to a life payment does not shield the body so much as tax the answer: an opponent can pay two life to point removal at it, but that payment lands on a total the cast trigger is already grinding down, and each answer they hold makes their own clock shorter. The two halves read as a matched pair by design. The entry sweep clears the blockers and shaves the planeswalkers that would otherwise trade with an attacker; the body that follows turns the rest of your hand into damage on its own.