If the Emerge card is a creature without flash, you cast it at normal creature speed, usually during your main phase while the stack is empty
Spider-Man is a pop culture icon, but that wont necessarily translate into record-breaking sales for a Magic set
Of course, Neriv doesn't have haste, and doesn't grant it, so if you want to make use of this, you better go all in on haste enablers
Same goes for Urza's Sylex
For a card at this value tier, a graded slab is the safest long-term home
Because all shrines are legendary permanents, specifically legendary enchantments, you can also use enchantress commanders, legends-matter commanders, and historic-matters commanders at the head of your shrine deck, but I wont include them here aside from some honorable mentions