Is it normal to take 2 turns for the first full moon boss in Merciless? I got humbled

I literally ran out of time after getting her to 25% health. Gave me flashbacks of Okumura but this one didn't even have a gimmick

In second turn it was a lot more smoother , cus I was using Fire to deal more damage . But still only 1 minute was left

But boi I got humbled so bad , I had platinumed P5R previously and cooked ( more like deep fried ) all the endgame bosses ( including Shido and Maruki ) in first try even without using endgame or DLC personas going in blind

Is this fight unfair because of Merciless/ early game ? Because I was able to cheese through the level 43 gatekeeper boss and had an easier time despite it having a gimmick ( kept knocking it down with critcials using that punch with small chance of status ailment)