Orzhov Advokist's ability doesn't target the creatures that receive +1/+1 counters. Their controllers choose them as the ability resolves. Players can't take actions between making their choices and the +1/+1 counters being placed.
Orzhov Advokist
If a player chooses to accept Orzhov Advokist's gift, that player can't attack you or a planeswalker you control with any creatures during their next turn, even creatures that weren't on the battlefield as Orzhov Advokist's ability resolved.
Orzhov Advokist's effect keeps creatures from attacking you even if Orzhov Advokist leaves the battlefield, if the creature that received counters is no longer on the battlefield, or if an effect has moved those counters off of the creature that received them and put them onto another creature.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Jason A. Engle
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
