Void Cubes

The Void Cube mod adds four decorative blocks that feature the end portal shader so that you can build your own void

There are two blocks, each with two variants. The regular variant's center ingredient is a blaze powder. The alt variant's center ingredient is an Eye of Ender.

The bordered versions are crafted by surrounding the ingredient with stained glass. The borderless versions are crafted by surrounding the ingredient with regular glass.

Credits

Ageuxo - Coding
oude_henky - Idea and border texture