I'm surprised no-one has at least mentioned Genex Ally Birdman His versatility easily allows for quick and often multiple Synchro Summons on the the turn in many different decks. When used in conjunction with possessing cards like Mind Control, he can remove threats and create significant board control. He makes great advantage of cards like Breaker, The Magical Warrior whose abilities trigger when they enter the field, as well as monsters whose abilities activate after being tribute-summoned, like the Monarchs (Once the Monarch is on the field, return it to your hand with Birdman, then use him as your new sacrifice). And, when paired with Reborn Tengu, he can instantly summon a level 7 Synchro. Give him a shot the next time you're looking to add a new flavor to your deck...