Sorry - I can never remember the name of the ocean between the Old and New Continent. *checks* Calistis Ocean. Basically the canal would run through Lucrecio from it's western coast to its eastern one, thereby opening up New Continent trade to the Coast of Commerce, breaking up Arlan’s near-monopoly on intercontinental trade, and putting Phaion in a stronger position, but obviously Lucanor would be getting something out of it as well - diverting a huge chunk of stuff from the New Continent through his principality so he can pluck out certain goodies as he sees fit. Phaion gains an economic edge and strengthens its position relative to Gabriel and Arlan, and also gains an ally against Dwänholf, as Lucrecio isn’t going to like its business disrupted by raids from pirate kings.
It’s all based on that thing that Lucanor, as the special little bunny he is, cleverly chose the only principality that:
a) has shores on both the Inner Sea and Calistis Ocean, thereby having uninterrupted access to the New Continent, Coast of Commerce, Varja, and even the likes of Kashmir & Baho.
b) has land borders to each of the Abel Empire (Kanon), Azur Alliance (Bellafonte), Episcopal States (Argos) and Al-Enneth (Kushistan).
Because him smart.