In fact, most spells want you to cast other spells, too, whether it's a Fervor in anticipation of your Terra Stomper or a boatload of cantrips to feed your Weather the Storm, casting spells on spells is how you win the game
If you're looking to make Anowon even stronger through upgrades, I would suggest adding more powerful Rogues like Thada Adel, Acquisitor, more ways to generate value through combat like Knowledge Exploitation, and finally more ways to plunder our opponents' graveyards like Mnemonic Betrayal
This card has different paper quality
Count the number of Auras you control as the ability resolves to determine the value of X
Once your speed reaches 1, you can increase it by 1 each turn when an opponent loses life, up to a maximum of 4
The Mystery Booster 2 Playtest Card Notes section (reproduced here in individual Gatherer rulings) provides guidance for fitting these cards into the existing rules structure