Megiddo

Dancing light rain down from the sky, it is reflected repeatedly above the ground, it pierces the a large number of enemies without meeting any resistance, resulting in a massacre.

Rimuru decided to invent a way to turn magic into pure physical energy. He took inspiration from Hinata’s disintegration, entrusting Great Sage to turn it into practical application. By entrusting all calculation, it was easy to put it into practical use.

He creates several hundred thousand floating water droplets in his surroundings. Far up in the sky, there are several dozen giant floating water droplets similar to convex lens. The convex lens shaped water droplets up in the sky receives sunlight and convert it into a thin line, down below the water droplets form reflective mirror array, that is used to converge it more. The water droplets are created by him with water spirit energy. Thus, the sunlight that the water droplets reflected, converge to become as thin as a pencil and its temperature reach thousand degrees. All the water droplets catch the sunlight energy, this is reflection converging magic.

This magic has a frightening aspect. That is, the energy cost is low. The water droplets created by the magic at the final point of the firing, will evaporate and disappear because of the heat, but it's possible to replace them in an instant. For that reason, he uses water spirit magic. The water can be created without using too much energy. This process can finish under one minute, and then it's possible to fire it again. After all, he only needs to replace the water and adjust its position. And, the magic power is only needed to maintain the water spirit. The energy source that contributed the most is the symbol of natural energy, the sun. The only problem is that it's only usable during daytime.

It took time to get used to it, but now he could control the beam according to his intention. The angle of reflection is simple, it's low cost, so he can shoot as many as he likes. If he converges the heat ray into a single spot, it will reach thousands degrees, so it will arrive at the point where it is possible to pierce a human with it. It's possible to shoot it optimally at will. There is only a little time lag, in other words, it is the same as the speed of light. For example, if he shoots it from 10,000 km, the time for it to reach the target is about 0.034 second. Even if a human eye receives information about it, the time for it to be transmitted and reach the brain is much slower. This calculation to aim precisely cannot be performed without using the Great Sage’s computation ability.

It works even on enemies who are escaping. It targets anyone he recognizes as an enemy.