Fireball is simple, create infinite mana and win the game
Cathedral of Serra Herald of Serra On Serra's Wings Radiant, Serra Archangel Sanctum of Serra Serra Serra Advocate Serra Angel Serra Angel Avatar Serra Ascendant Serra Avatar Serra Avenger Serra Aviary Serra Bestiary Serra Disciple Serra Faithkeeper Serra Inquisitors Serra Paladin Serra Paragon Serra Redeemer Serra Sphinx Serra Zealot Serra the Benevolent Serra's Blessing Serra's Boon Serra's Embrace Serra's Emissary Serra's Guardian Serra's Hymn Serra's Liturgy Serra's Sanctum Serrated Arrows Serrated Biskelion Serrated Scorpion
Indicate if you want to alternate between Pokmon)
Theres also a subsection of copy spells that recognize a particular instant and sorceryoften by exiling itand allow you to produce multiple copies of that particular spell
Trading in 3 mana (2 to activate and the opportunity cost of tapping Fountainport for colorless) and a token for one card isnt the most efficient sac-for-card trade that there is, but youre paying a tax for the modality of all the other abilities and the fact that its a land, not a creature or something
Urza is so good in the format that it even spent some time on the Game Changers list, though it was freed from those shackles late last year