으니라고

Theatrical scolding: 'you fool!'

Every line here is the fixed frame 같으니라고, which follows an insult to make it a full exclamation: 이 괘씸한 미국 사람들 같으니라고! 'those sneaky Americans!' and 바보 같으니라고 'you idiot!' It sounds like a scolding elder in a period drama, so today it is nearly always played for laughs. The 이 in front of the insult (이 고얀 놈 같으니라고) is part of the same theatrical package.

Register: theatrical scolding, old-fashioned