[
    new MagicWhenAttacksTrigger() {
        @Override
        public MagicEvent executeTrigger(final MagicGame game,final MagicPermanent permanent,final MagicPermanent creature) {
            return (permanent.isFriend(creature) && game.getAttackingPlayer().getNrOfAttackers()==1) ?
                new MagicEvent(
                    permanent,
                    creature,
                    this,
                    "RN gains double strike until end of turn."
                ):
                MagicEvent.NONE;
        }
        @Override
        public void executeEvent(final MagicGame game, final MagicEvent event) {
            event.processRefPermanent(game, {
                final MagicPermanent permanent ->
                game.doAction(new MagicGainAbilityAction(
                    permanent,
                    MagicAbility.DoubleStrike
                ));
            } as MagicPermanentAction);
        }
    }
]