Now why is Jenti with i and voktī with ī, I mean vokti isn't plural, it's 1 priest, I thought ī was used when it's plural
In this case, it's the same as in the very first lessons, where the elongated vowel meant that the noun was "and the priests".
And the priest (singular) ;). I wonder if you could say "Jenti se vokti urnen" though or if you use "se" only between two actions, for example "Taoba kirine issa se edrus." (sorry no keyboard for the long e).