A great majority of the Jalhalla fight is based around speed and efficiency: during his first phase you must quickly reach a beam of light and use it to solidify Jalhalla, before two of the beams randomly fade away. Once you have made him solid (the second phase), you must toss Jalhalla into one of the spiked pillars to split him into 15 poes. The best and quickest way to dispatch of them is by using elixir soup to deal double damage so that you can kill a poe with a single sword slash. However if you take too long, Jalhalla will spawn back after 15 seconds and you will be faced with an extra cycle.
Although the Jalhalla battle is relatively straightforward, it does contain a number of crucial limits that must be kept in mind. Firstly, the minimum number of cycles that Jalhalla can be defeated in is three. As he is composed of 15 poes, this means that typically in each cycle you can only defeat a maximum of 5 poes before Jalhalla respawns. However there is a slight exception: you can kill 6 poes in one cycle (by killing the 5th and 6th with the same blow). But, this means in the following cycle that you will automatically be limited to killing only 4 poes. This is a relatively rare happenstance though, and most of the time even if you deliver a finishing hit to a sixth poe it simply will not die and Jalhalla will respawn.
Due to the fact that you need to lift Jalhalla from the ground to split him up, the power bracelets cannot be skipped in a low% run — this being the one and only instance where the item is required.
With a good aim, arrows can be used to kill the poes in the second phase. This doesn't necessary save time though, unless you are very quick at aiming — as it takes two arrows to kill one poe. But due to the mechanics of how arrows continue moving and having the potential to deal damage until they hit a solid surface (like a wall), you can hit poes in one shot if they are lined up with each other.