When Ainok Guide enters, choose one — • Put a +1/+1 counter on Ainok Guide. • Search your library for a basic land card, reveal it, then shuffle and put that card on top.
2014-11-24
If a mode requires a target and there are no legal targets available, you must choose the mode that adds a +1/+1 counter.
2014-11-24
You choose which mode you're using as you put the ability on the stack, after the creature has entered the battlefield. Once you've chosen a mode, you can't change that mode even if the creature leaves the battlefield in response to that ability.