In v4.0.9 for Minecraft 1.20.1, the ritual recipe for Infernal Pixies uses Infernal Dust instead of an Infernal Shard. Since this sets it apart from all other pixies at that level, I figured it might be unintended.

Thank you for the report, but this is intended behavior. Because Infernal pixies explode and have to be resuscitated between every use, it didn't feel fair to charge a full shard to summon them in the first place.