Personally, I always go for the Artemis' Aid, because it's a pretty solid Call, but honestly you can go with any of these. None of them particularly help you with the cast build itself, but they are a requirement to get the duo boon.

Hunter Dash: ' Your Dash-Strike deals more damage.'.Deadly Strike: ' Your Attack is stronger, with +15% chance to deal Critical damage.'.Deadly Flourish: ' Your Special is stronger, with +20% chance to deal Critical Damage.Artemis' Aid: ' Your Call fires a seeking arrow with +35% Critical chance.'.To get the duo boon, you'll need the aforementioned Slicing Shot and at least one of the following Artemis boons: The Slicing shot's biggest problem is that it will only hit the enemy for a portion of it's duration, something that the duo boon Hunting Blades completely eliminates, and you'll see your cast deal thousands of damage as they track your enemies With just this two boons you'll melt through anything the game throughs at you. Artemis' & Ares' Hunting blades: 'Your Cast creates a faster Blade Rift that seeks the nearest foe.Ares' Slicing shot: 'Your Cast sends a Blade Rift hurling ahead.Well my friend, I have the cast build for you.

If you are like me you probably don't use the cast that much most of the time, not because it's bad or anything, but just because your playstyle makes it so that using cast isn't that much fun.

Hades demeter cast build