What is your reason for that
Note that the listed prices correspond to the date of this article's publishing: July 07, 2021
The most common way is the suspend mechanic, like on Search for Tomorrow or Sol Talisman, which lets you exile a card from your hand, put some time counters on it, and then cast the card for free when those counters are gone
Planeswalkers currently have the legendary supertype attached to them, regardless of when they were released
The first DailyMTG article about Cube, written by Tom LaPille, was published in 2009
If that happens before the declare blockers step, it may allow those tokens to be blocked by creatures without flying