It doesn't matter if he was smiling. Madara is the type of guy who would be having a thrill even if he was getting his ass kicked. Gai was destroying him with speed and power. Only reason he survived was because of his op juubi stamina.No. Madara wasnt serious
If you seen the manga you could see that he was smiling all the time as if it was a joke. A game
Madara was just playing with him. Guy was nothing