These multi-stage spells are usually reserved for Enchantments and accumulate different effects each turn with the addition of lore counters
Summon: LeviathanSummon: Leviathan, in particular, is extremely potent in such builds as it delivers a Whelming WaveWhelming Wave for its first chapter and then draws you a card whenever one of those creatures attacks (a trigger for each one, that is)
I prefer Miara, Thorn of the Glade by far, but pairing them together is respectable
Then your spells from non-hand sources also get a mana reduction, but this time just one
Creature - Knight Angel Gix, Yawgmoth Praetor Whenever a creature deals combat damage to one of your opponents, its controller may pay 1 life
To be honest, I value the top two about equally and recognize that there are advantages and disadvantages to both