[Cantare] is an interesting weapon. The entire strength of these throwing knives lie in the extra 300% critical chance when they return to the thrower. For this reason, I build [Cantare] with no critical chance and as much critical damage as you can get without a riven. I am trying to get a crit damage riven for these but I haven't succeeded yet.
Punch through is extremely good as the returning knives have infinite punch through. This means the more enemies you can throw Cantares through going out, the more enemies it will hit upon return. However, if you can only throw the knives through two enemies going out, it will only hit two enemies on return.
[Synth Charge] applies its buff to ALL returning knives.
Faster reload is also extremely good on Cantares because it means you can fire faster upon return and increase the uptime of returning knives but I couldn't fit in into this build.
The damage on this build won't look good here but it's absolutely insane. Cascadia Flare activates very quickly because both the thrown and returning knives proc heat.
You can also use these with [Qorvex] for his additional +4 punchthrough and remove [Seeker] from the build in favor of reload speed. I like [Stunning Speed] for the extra status chance.
I tested projectile speed and unfortunately it doesn't increase the return time or speed of the knives.