Gandalf the White

Doubling triggers is old white magic, but this reads the doubler as a legendary-and-artifact engine rather than a token or lifegain one, which reframes what a value permanent even is. The two clauses reinforce each other with intent: granting flash to your legendary and artifact spells means you deploy the very permanents whose entrances and exits it doubles, and you do so at instant speed, so the doubling lands on your opponents' turn as easily as your own. That flexibility is the real design lever. A doubler that only worked on your main phase is a build-around; one that lets you flash in a legendary or crack an artifact in response to a removal spell, catching two triggers off the leave-the-battlefield event, is something else entirely. The trigger clause is deliberately symmetric about entering and leaving, unusual for effects in this family, which tend to care only about entrances. It doubles death triggers, sacrifice payoffs, and blink value on artifacts and legends alike, folding the "when this leaves" half of the battlefield into the same engine. The 4/5 body with flash is not incidental either: the whole package can be held back as a surprise blocker while you keep mana open, then committed the moment a doubled trigger pays off, rather than tipping your hand a turn early. It rewards patience without asking you to sit dead on an empty board.