2022-09-09 : Domain abilities count the number of basic land types among lands you control, not how many lands you control or how many of any type.

2022-09-09 : If Zar Ojanen becomes tapped while casting a spell or activating an ability, that spell or ability resolves after Zar Ojanen’s triggered ability has resolved.

2022-09-09 : The basic land types are Plains, Island, Swamp, Mountain, and Forest. Land types other than basic land types (such as Desert) don’t contribute to domain abilities.

2022-09-09 : Zar Ojanen, Scion of Efrava’s ability is a triggered ability, not an activated ability. It doesn’t allow you to tap it whenever you want; rather, you need some other way of tapping it, such as by attacking.