mtg whenever an opponent draws a card o:"whenever player a card" or o:"whenever draws a card" or o:"whenever you draw a card" · Scryfall Magic: The Gathering Search You draw a card for each card drawn this way Trade Secrets MTG - Onslaught

While its ability to endlessly regenerate itself is one thing, being able to mill six cards from the top of your library instead of drawing every turn is just too powerful of an effect for players to be able to access for free

None of these abilities has a duration

For example, Delver of Secrets has a triggered ability occurring when you reveal an instant or sorcery from the top of your library while Bloodline Keeper has an activated ability with a cost to transform it (in this case, paying a black mana)

Does Transforming a Creature Remove It From Combat

You may cast any number of spells with total mana value 10 or less from among them without paying their mana costs