Artslam 4-5

Souls that continue to hold a grudge even after death are known as Vengeful Souls. Although they are harmless in their normal form (like all other souls), they are ruthless killing machines when transformed. Every claw and spine on their body is tipped with poison, and on top of that they can spit poison from their mouths. Once transformed, they will carry out their master's orders until death.

Proud Souls are often the souls of those who wielded power before death. Once transformed, they will obey their master's orders without question. They do not have an actual material form, their souls simply occupy the spaces in the armour. The crystal on their shields contains their main essence, and they are defeated once this crystal is destroyed. Although it is displayed prominently on the shield, it takes a great force to actually shatter the crystal. The colour of the crystal and their soul essence can vary, depending on their personalities when they were alive.

If any of these designs look familiar... Vengeful souls are kind of a bastard cross of xenomorphs and zerglings, and I kinda-sorta stole the Proud souls armour design from the Angelo mobs in Devil May Cry 4.