Exert Influence

Converge as a sliding price tag: the more colors of mana you funnel into the cast, the bigger the creature you can steal, capping at five colors and a power of five. That structure makes a mono-blue card secretly reward a rainbow manabase, which is the entire design conceit. Among blue's theft effects, this one is the awkward cousin: Control Magic and Mind Control hand you the creature outright at a fixed rate, while this asks you to pay in color diversity rather than raw mana, and to accept a ceiling that only the most ambitious manabases lift past three or four. The sorcery speed and the power restriction together make it a deliberate piece of friction; you cannot snap it onto a freshly resolved threat at end step, and the largest finishers stay out of reach unless you have genuinely assembled five colors of fixing. What it represents is converge being asked to carry a marquee effect rather than a marginal bonus: most converge cards scale a number of counters or damage, but here the color count gates whether the spell does anything at all. A two-color cast might whiff entirely against a 3/3, which is the tension the card lives inside. It is theft built to make you earn your manabase, an effect whose ceiling is real but only opens for decks that committed to the gimmick the keyword was selling.