My take on Horde Prime, based off the little info in season 3.

This is just my speculation on what he may look like.

[ID: a digital drawing of a tall buff alien character. He has dark blue skin except for the front of the face and top of the ears, which are white, making his face look skeletal. He has glowing red eyes and dark blue undercut hair, and a huge scar going across his eye and mouth. There are scars on his arms too. He’s wearing black armor on his body, and gray metal armor on his forearms and legs, and a cape with a standing collar.]