If your tenth permanent enters the battlefield and then a permanent leaves the battlefield immediately afterwards (most likely due to the "legend rule" or due to being a creature with 0 toughness), you get the city's blessing before it leaves the battlefield
But despite all their power and their glory, the high Tribute costs of these monsters have always made them a risky strategy in tournament play
I even had an elemental rampage thing happening at one point, with Groundbreaker, Fusion Elemental and some other stuff
Note that +1/+1 counters/Food tokens don't have a mana cost, so their mana value is 0
There are also some cool interactions along with it, including but not limited to pairing it with Zur, Eternal Schemer to smash someone with a heavy-hitting enchantment
2 foil promo cards featuring Victini and Zoroark