Legendary Creature — Halfling Rogue
Whenever a player casts their second spell each turn, you lose 1 life and create a Treasure token. (It's an artifact with ", Sacrifice this token: Add one mana of any color.")
2/1

White treasure-style ramp punishing opponents' actions, similar payoff engine.

Another low-cost legend that rewards casting spells with value.

Treasure generator triggered by spellcasting for storm/ramp synergy.

Doubles Treasure tokens Lotho creates for extra ramp.

Treasure payoff and alternate win condition pairing with Lotho's tokens.

Pings opponents whenever Treasures or artifacts enter, leveraging Lotho's tokens.

Sacrificing Treasures becomes a drain finisher with Lotho's output.

Drains life as Treasures are sacrificed, complementing the token engine.
Spells that were cast before Lotho, Corrupt Shirriff count. If Lotho, Corrupt Shirriff was the first spell you cast this turn, the next spell you cast this turn is your second spell.