I need some help!

[rexyplaysmtg]

Ok, y'all. I need to find a card that grants me the ability to use loyalty abilities of planeswalkers on any player's turn when I could cast an instant. And no, I am not looking for Teferi, Temporal Archmage; I need a mono-white permanent that is either a creature or enchantment if possible. I just hope this exists. Thanks.

[void_nothing]

No such card exists. Oath of Teferi and The Chain Veil let you double up on loyalty abilities, and Teferi, Master of Time has instant-speed loyalty abilities for itself, but in white only The Wandering Emperor can activate its own loyalty abilities at instant speed (and only on the turn it ETBs), and only that Teferi's emblem gives you this effect universally.

Ultimately there's not a lot of cards that directly affect loyalty abilities, and although there's a lot of design space and such cards are being printed more freely now, I wouldn't expect to ever see Teferi's emblem effect on an independent card, just because of how tremendously powerful it is.