Primal Split's Earth, Storm and Fire spirits have separate despawn animations. Why are these not used? It makes much more sense than to have them die. Them dying is supposed to mean death for Brewmaster as well. This is a big thematical flaw right here.

The despawn animations are even shorter than their death animations, so it would cause clutter or confusion. It only needs some particle effects to go along with them.

Storm and Fire could be made to dissipate into the air (similar to what their death anims currently do), and Earth could be made to quickly sink into the ground, leaving a small temporary rock-filled hole behind, instead of crumbling down like its death animation.

Here you can see their despawn animations. I usually wouldn't suggest this kind of stuff, because it's too much work for such a little thing, but in this case, the required things already exist. The animations are there, and the particles can be quickly adapted from the already existing ones they use.