Last time I played was I think when the warlock class was introduced.
Back then Lagons boss fight had a siginificantly different theme. One I personally found way more fitting than the odd happy-go-lucky tune that plays now in the Seafloor colosseum.
It sounded ‘big’, like you were about to fight an absolute leviathan. It had the ambience, this sense of urgency and danger and that you’re facing truly something far beyond yourself in terms of power. It was glorious. That’s easily the best word I could describe the old theme with.
For those curious, here’s a timestamped video of the old OST. It starts at Lagons theme.
My feedback is basically, perhaps revert that music change. It is really not fitting and frankly kinda detracts from the ambience. Lagons Temple also had a very odd and unfitting new tune.