The ability to cast any legendary spell, not just creatures, for three mana while you have a tapped creature to spare is a big deal
And having conditions that dont fade when a card goes into the graveyard or exile also feels like a big change from how Magic has worked since, well, forever
There are so many fun ways you can use this, but it is also a great resource to have in your classroom for when students have a bit of downtime.
(2/2 being a solid base strength b/c it's neither trivial nor terrifying and it leaves room for clever adjustments, as you'll see)
Wizards of the Coast has made something quite special, but, with some degree of collaboration with its player base, they've made something even better in the form of the Commander format
After you sweep the board, you just return your lands while your opponents are left with nothing