One of his most common is a large inhale-exhale attack. If you get close to him on the inhale, he’ll blow a stream of flames at you. If you manage to stay away, he’ll exhale and blow you towards the spikes around the room. When you get close him at other times, he’ll usually let loose a stream of fireballs from his lantern.
His least-used attack (in my experience) is the jinx that will reverse your controls like a normal Poe does. However, he won’t sacrifice himself in any way. Usually, shining a beam of light on him (you’ll understand in a second) will cancel his attack, no matter what it is.
So, how are you going to retaliate? Well, doesn’t he look like AND is made up of normal Poes? And what is the main weakness of these ghosts? No, not an exorcism, but light! Have Link enter one of the beams of light surrounding the arena and lock-on to Jalhalla. Defend and, if you’re in the beam of light, some light will be reflected onto the boss, ending whatever attack he is doing.
In addition, if you hold the light on him long enough, he will be stunned, become solid, and drop onto the floor. Have Link run over to him and pick him up. Aim towards one of the spiked cylinders around the arena, and throw him at it. While Jalhalla is rolling, charge up the Hurricane Spin, if possible.
Once the enemy hits the spikes, he will hop into the air and split into about 15 Poes. When the Poes hit the ground, let loose with the Hurricane Spin! If you control Link well, you’ll take out about half of the Poes. They will reform into Jalhalla after some period of time. After they do, rinse and repeat.
After the last Poe has been defeated, Jalhalla’s mask will appear, as if it is expecting to absorb at least one Poe. However, it notices there are none and begins to run away and float up a spiked cylinder.
However, before it can leave, a beam of light shines down on the mask and the mask explodes, leaving behind a complete Heart Container . The center upside-down triangle of the Triforce emblem in the middle of the room also begins to glow blue. Grab the Heart Container and enter the light.