It can come down and immediately trigger at least two landfall proliferates the turn it is played (and potentially more, if you sequence correctly)
It fit with Asmira perfectly, right down to the gorgeous art
Whether it falls under the categories of artifact, battle, conspiracy, creature,dungeon,enchantment,instant, or land
If the targeted creature becomes an illegal target before Unagi's Spray resolves (perhaps because it left the battlefield), the spell will not resolve
Its not the most generic tutor, but it works well with commanders that want to cast spells from the graveyard like Kess, Dissident Mage and Sevinne, the Chronoclasm