Card draw and hand attack are always good, so whatever Grixis strategy youre running, theres a good chance he can make it better
The only issue, assuming you don't consider costing ten mana an issue, is that resolving four cascades in a row can get complicated, especially when individual cascades hit other cascade spells mid-resolution
It slots nicely into Treasure decks to take advantage of cashing those tokens in for mana, and its elf creature type helps it fit into Lathril, Blade of the Elves token decks
Whenever you visit that Attraction, copy the exiled card
Remember that Rashmi triggers any time you cast the first spell of a turn, no matter what you cast
Bonus points if you dropped a Colossal Dreadmaw in your graveyard in time for the final stage