Domain — Whenever Zar Ojanen, Scion of Efrava becomes tapped, put a +1/+1 counter on each creature you control with toughness less than the number of basic land types among lands you control.
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.
09-09-2022
wotc
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.
09-09-2022
wotc
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.
09-09-2022
wotc
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.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.