Mark, I've got to say I'm really glad Wicker Picker survived all the times it was almost removed from Unfinity. It's not only hilarious, but it has revived interest in an old kicker deck I made when I first started playing Commander, and gives me an avenue to add stickers into the mix with my commander group!

I too am happy it stuck around. I do like the card. There just were a lot of cool cards fighting for space.

Ok, so hear me out:

1) My opponent controls a Wicker Picker.

2) I use Mindslaver to control their next turn.

3) In this turn, I play a creature from their hand, and I use Wicker Picker’s sticker kicker.

Since I am in control of my opponent’s turn, can I put a sticker on the Sticker-kicked creature?

Does the answer change if I used “Donate” to give them my Wicker Picker in the first place?

(Also, one thing I’ve realized from past answers is that if my opponent doesn’t want a sticker glued on their card, we can use a counter. I can’t force them to use stickers with real glue).

You cannot. Same with Donate. There are no cards currently in the game of Magic that change ownership of cards (well, except ante cards, but those haven’t been a thing in a long, long time and they are banned in every format).EDIT: Some further clarification. Built into the sticker rules is you have to voluntarily choose to put a sticker on a card. Nothing in the game can force you to sticker something if you don’t want to sticker it.EDIT #2: Checking into this, I gave a slightly incorrect answer. If you Mindslaver your opponent, you can force them to sticker cards they own, but you can’t literally force them to put a sticker on it. The player may choose instead to represent it with paper and pencil.

You keep saying stickers only go on cards you own, but Wicker Picker lets you sticker any creature spell you cast, and plenty of effects let you cast cards your opponents own. Is "stickers can't go on cards you don't own" enforced by the game rules then, Wicker Picker tries but fails to sticker a spell you don't own?

Yes, the larger sticker rules only allow you to sticker cards you own. Sticker cards generally say that. Wicker Picker used a different template because you normally only cast cards you own, and we didn’t feel like writing a bunch of extra words, so we let the larger sticker rules cover it instead.

Is the rule you can only sticker cards you own *on the cards*?

Yes. Barring other templating concerns (like Wicker Picker) it says “put a sticker on a nonland permanent you own”. Some, like Angelic Harold, might limit what kind of sticker you can use.

Hey quick question if someone uses Etali to cast a creature from the top of my deck and Wicker Picker to deface that creature with a sticker, to whom do I file the complaint?

You can only sticker cards you own, so no one else can sticker your cards.

Doesn't Wicker Picker let you sticker your opponent's cards when you cast them the way it's written?

No. Baked into the sticker rules is you can only sticker nonland permanents you own.