Kate Stewart
Legendary Creature — Human Scientist
Whenever you put one or more time counters on a permanent you control, create a 1/1 white Soldier creature token.
Whenever Kate Stewart attacks, you may pay 
. If you do, attacking creatures get +X/+X until end of turn, where X is the number of time counters among permanents you control.
Thanh Tuấn
Doctor Who (WHO)
• #1013Rulings
Similarly, its last ability counts only time counters on permanents, not on cards you own in exile.
(wotc • 2023-10-13)
Kate Stewart's first ability triggers only when you put time counters on permanents. It does not trigger when you put time counters on cards in exile.
(wotc • 2023-10-13)
Rulings
Similarly, its last ability counts only time counters on permanents, not on cards you own in exile.
(wotc • 2023-10-13)
Kate Stewart's first ability triggers only when you put time counters on permanents. It does not trigger when you put time counters on cards in exile.
(wotc • 2023-10-13)