High Fae Trickster

Granting yourself flash on every spell converts a decklist built for sorcery-speed sequencing into an instant-speed toolbox, and that quiet static line reshapes the game far more than a flying 4/2 body would suggest. Creatures wait for combat surprises, planeswalkers deploy while the opponent is tapped out mid-attack, sorceries suddenly ambush the stack. It is a flexibility engine wearing the clothes of a beater. What pays for how sweeping that flexibility is: the granting lives on two toughness, so the effect dies to almost any burn spell, and the window it opens lasts only as long as the body carrying it survives. A hexproof or armored version of this would warp deckbuilding past what a four-mana creature should be allowed to do; the liability is the price of the reach. Because the card has flash itself, the flying threat and the flash-granter arrive in the same held-up window on the opponent's turn, and from there every card in hand becomes a potential response. The lineage runs through Vedalken Orrery and Leyline of Anticipation, effects that hand you instant-speed access to your whole hand. The difference is durability: those sit on permanents built to endure, cheap or free, while this staples the same effect to a creature the opponent is actively incentivized to kill. Identical flexibility, wrapped in a clock and a target.