"Jaes sȳri voktī jorrāelza."

Translation: The god loves the good priests.

[AbouAurora]

Is it voktī and not voktyssy because of the fact that the verb is acting on the priests?
I'm a bit confused ...

[SprightBark]

Yes, despite your confusion you have it right! :-D

priests
nominative (does the verb): voktyssy
accusative (the object of many verbs): voktī

And in the singular priest
nominative: voktys
accusative: vokti