The cost reduction applies only to generic mana in the total cost of spells you cast with the permission granted by Urianger Augurelt's last ability
For example, if there are two +1/+1 counters on Aerith Gainsborough and it gets three -1/-1 counters, you'll put two +1/+1 counters on each legendary creature you control when Aerith Gainsborough's third ability resolves
Think weve missed something major
After the first set of cards in Legends and a few other sprinklings, many of which established that gold cards would be consistently more powerful than their competition, gold came into its own in Invasion block
Players can Shift, and play this card on another Kronk card for a lower cost of 5 Ink, and when this character banishes another character, the player can play a character card with a cost of 5 or less for free
You must sacrifice exactly one creature to cast this spell