Winter is a commander that can cheat out strong cards early if you're lucky enough to mill them
Along with this, at the beginning of your end step, you'll create a 0/0 red Gremlin artifact creature with X +1/+1 counters on it, where X is the number of differently named artifact tokens you control
As well as the cereal choice at the start or the two music choices (the tape Stefan picks on the bus ride and the record he buys in the shop), there's the impulse you want Stefan to make in the therapist's office (he'll resist it either way), when Stefan gets given a higher medication dose after Colin tells him his theory about mind control (he'll either throw his pills in the bin or flush them down the toilet), or anything to do with the fourth-wall breaking "Netflix" ending (with one choice between "Yes" or "Fuck Yeah", both leading to a massive unrealistic fight scene)
It can be found in the Mega Gyarados pack from the MegaRising set
It's usually a glow on the card, acting as a coat over it, which generally makes it weigh a bit more than a regular foil card