[
    new MagicWhenAttacksTrigger() {
        @Override
        public MagicEvent executeTrigger(final MagicGame game,final MagicPermanent permanent,final MagicPermanent creature) {
            return (permanent.isFriend(creature) && 
                    permanent.getController().getNrOfAttackers() == 1) ?
                new MagicEvent(
                    permanent,
                    creature,
                    this,
                    "RN gains lifelink until end of turn."
                ):
                MagicEvent.NONE;
        }
        @Override
        public void executeEvent(final MagicGame game, final MagicEvent event) {
            game.doAction(new MagicSetAbilityAction(event.getRefPermanent(),MagicAbility.Lifelink));
        }
    }
]