If there's a cost associated with having that creature attack, you aren't forced to pay that cost, so it doesn't have to attack in that case either
Casting an efficient removal or card draw spell multiple times for free (if you can flicker or otherwise trigger the Chancellor) can give you a solid advantage, and the fact that ramp and spells get better every year means this card does, too
This means that you can expect to find it in every set on at least a few cards
Of the fourteen cards, ten will be common, three will be uncommon, and one will be rare or mythic rare
Creating a draw chain like this can easily allow you to hunt down the pieces for a combo win
Teyo makes a 0/4 White Wall with flying and defender on arrival to the battlefield to block attacks on Teyo, planeswalker friends, and then you too