Whenever you cast a modal spell, choose up to X, where X is the number of times you chose a mode for that spell —
• Exile the top card of your library. Until the end of your next turn, you may play it.
• Put a +1/+1 counter on Riku. It gains trample until end of turn.
• Create a 1/1 blue Bird creature token with flying.
Riku of Many Paths rewards you for casting modal spells—cards with charm/command choices, escalate, choose-one-or-both, and entwine. Each time you cast one, you trigger Riku and pick value modes (card advantage, growing Riku, or Birds) equal to how many modes the spell selected. You grind incremental advantage across the early-to-mid game, then close out by going wide with Birds, swinging with a trampling Riku, or comboing/storming off with cheap modal spells.
Engine that converts modal spells into card advantage, board presence, and a growing threat simultaneously
Three colors give access to the deepest pool of charms, commands, and escalate/entwine spells
Flexible payoff—can pivot toward go-wide tokens, Voltron, or value control depending on draws
Self-mill/impulse-draw mode keeps your hand stocked with more modal spells
Highly dependent on building a critical mass of modal spells; off-theme cards do nothing for the engine
Riku triggers off casting, so countermagic and removal on the stack/commander shut you down
Bird tokens are fragile to board wipes and you can fall behind without the engine online
Three-color manabase strains consistency and many modal spells are mana-hungry to maximize modes
Ramp and value that helps you afford the mana-intensive multi-mode spells Riku wants every turn.
Raise the modal-spell count and lower the curve—add cheap split cards, Charms, and escalate spells so Riku triggers every turn for little mana. Layer in spell-doublers (Bonus Round, Thousand-Year Storm), cost reducers (Goblin Electromancer, Baral), and token payoffs (Parallel Lives, Craterhoof Behemoth) to convert triggers into wins. Tighten the manabase with fast lands, signets, and Smothering Tithe so you can reliably afford multi-mode spells.