Big Bad Akantor, big "flying wyvern", spiked all over, he gets a specific arena that you get to fight him in. Ingle Isle, a big ol' island that slowly rises from the sea and you fight Akantor on a plateau that gives you a view of the sea and the volcano above you. The arena was decked out back in MH4U, so it gives some interesting leway in your fights, little steps allow you to get a edge on Akantor so you can possibly mount him, one of his attacks has him bodyslamming the floor pushing down parts of the arena which you must climb out of.