When paying Jötun Grunt’s cumulative upkeep, you may choose a different graveyard for each age counter. For example, if it has three age counters on it, you may put four cards from your graveyard on the bottom of your library and two cards from your opponent’s graveyard on the bottom of his or her library. However, you can’t put five cards from your graveyard on the bottom of your library and one card from your opponent’s graveyard on the bottom of his or her library.