Pretty much all of the Swords of X and Y are fairly pricey, and this one has only had Modern Horizons Timeshift and Secret Lair reprints to soften the price
each retains their set code and card number, with the only difference from the original card being the foil treatment and snowflake stamp
According to the domain registry, their domain was registered in 2018
Beginning phases and steps[] When a phase or step begins, any abilities that trigger "at the beginning of" that phase or step are added to the stack in the "Active Player, Non-Active Player" (APNAP) order
That is why it works for 30-100 cards but no more or no less
There are a ton of reasons why this is possible, from variance to match-ups, but because of this, I am dropping Gimbal down two ranks