why does mark have robot arms

Mark Grayson, the protagonist of the "Invincible" series, is seen having robot arms as teased in the season 4 trailer of the "Invincible" animated series. The trailer shows Mark wearing Robot's arms and one of his legs, described in the script as "METALLIC CASTS" on his body. This happens after an incident in space where Mark is knocked out by a monster amid metal space debris. While the exact reason why Mark has robot arms has not been explicitly explained yet, it appears tied to events happening in season 4, laying the groundwork for upcoming action-packed events.