Sakuya Izayoi, Timeless Maid

Reach, Vigilance
Whenever a phase starts or ends during your
turn, if an ability triggers under your control, it
triggers an additional time.
{7}{w}{u}{b}, {t}: The player whose turn it is ends
their turn. (Exile all spells and abilities on the stack.
That player discards down to their maximum hand
size. Damage wears off and "this turn" and "until
end of turn" effects end.)