Creatures cant be attached to other permanents
Aside from the far-reaching implications of these modal lands, the new party mechanic (which provides another application for Umara Wizard) promises to add another interesting consideration to deck-building, and landfall is always fun for the weight it adds to every land drop
To start with, yes, you can absolutely do this
While its not Blasphemous Act, I can see this card going in a LOT of decks between the convoke, large mana cost, and many token strategies
Prerelease foil: $26 to $30 Foil: $20 to $22 Regular: $16 to $17 Leyline Binding The DMU Enchantment Leyline Binding has impacted Magic formats like Modern, Pioneer, Commander, and even Standard
Since you spent the turn cheating an octopus into play, Unagi's Spray can be just the trickery you need to defeat an attacker or trigger a second draw