Cryonis

Aim at the water, not at the riverbed you can see through it. A pillar under a floating or sunken chest lifts the chest to the surface so Magnesis or your hands can take it. Two pillars in a line are a bridge. Climb the flat top. They melt in hot areas and shatter if you hit them.

On the way to Zora's Domain, Octoroks and Lizalfos shoot from the water, and water spouts knock you off the path. A pillar in the spout blocks it. A pillar in front of you blocks the rock spit. You do not have to kill every shooter on that road.

Cryonis needs a water surface. It does nothing on lava, swamp mud, or a thin puddle on stone. It also cannot form under a solid dock. Step to the side until the reticle finds open water.

You unlock it at the Keh Namut shrine on the Plateau, and there is no upgrade. Three pillars is the whole kit. Break one with a weapon if it is in your way instead of waiting. In a shrine, a pillar under a floating platform is often the intended step, so try the water before you burn a bomb.