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.
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.
24-11-2014
wotc
If a mode requires a target and there are no legal targets available, that mode can't be chosen. You must choose another mode if able.
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.