It is exponential in terms of value
It is a one-mana legendary monkey pirate creature at 2/2 that, when it deals combat damage to an opposing player, creates a treasure token and exiles the top card of the defending player's library, and you can cast that card until the end of the turn
We want as many cards in the Trash as possible, especially in the early stages of the game
The trample from Rancor, Shadowspear and Loxodon Warhammer pairs up quite nice with double strike
Thassas Oracle costs two Blue and allows its controller to look at the top X cards of their library where X is their Devotion to Blue (in other words, the number of Blue pips in the mana cost of cards they control)
If it gets put straight onto the battlefield, it skips the spell stage completely