Flood San 'Shyuum Form

Prophet Form is a term fans have created to describe Covenant Prophets that have been infected and overtaken by the Flood. Due to their unusual nature, they are not thought of as Combat Forms in the way infected Humans and Elites are. Note that the term "Prophet Form" has not been officially used as canon to date.

It is also worth noting that both "Prophet forms" seen had only just been infected, and may not have been assimilated in the conventional way. The only prophet to be seen being taken by an infection form was the Prophet of Mercy. However, Master Chief removed the infection form, and Mercy died.

Appearance
The Prophet Form maintains the same general appearance as a Prophet, but with decayed skin and appearance of a standard flood form. If they are infected by Infection Forms, the form does not show, as their sensory stalks are not visible on the Prophet. This does not mean that the Prophet is kept completely intact- the assimilated Prophet of Regret had only a single, malformed arm, and was impaled by one of the Gravemind's large tentacles. Also, a human skull can be seen in the top right corner of the prophet form, which is probably a part of another assimilated being.

Differences with a Combat Form
The biggest difference between Prophet Forms and the conventional Combat Form is that Prophet Forms maintain their personalities to an extent. Combat forms are essentially zombies- they have no sensory organs or cognitive capability remaining, being completely controlled by an Infection Form. On the other hand, Infected Prophets have demonstrated the ability to see, hear, and talk, and even act the same that they did before they were assimilated. In this sense, they seem to be more advanced than Brain Forms.

It appears that they sometimes operate as part of a Brain Form, as the Prophet of Regret appeared to be attached to the Gravemind. In the case that there is no Brain Form present, the Prophet Form acts to an extent as the leader of the Flood in the area. Also a skull can be seen in the top left corner of the prophet form. Looking just below the "prophet form" the hand of an elite can be seen as well. No other forms of flood contain skulls.

Personality
Two Prophet Forms have been encountered, each having radically different personalities. The Prophet of Regret, after being assimilated by the Flood, appeared to maintain his previous personality, almost oblivious to the fact that he was assimilated. This could be either because he was still partially alive, or because the Gravemind was merely controlling him like a puppet. The Minister of Etiology, on the other hand, was completely unlike his previous self. He acted as a spokesperson for the Flood, even taunting Rtas 'Vadumee saying, "The Forerunners not defeat us, what chance you?"

These personality ideas may be related to the command structure of the Flood in the area. In Regret's case, he was only a part of a larger intelligence, the Gravemind, so his personality did not need altering. The Legate on the other hand, appeared to be the controlling intelligence of the local Flood because the Brain Form on the ship had been destroyed.

''NOTE: There is a great deal of controversy on the very existence of the Prophet Form. This article is only for the sake of observing the phenomenon of assimilated Prophets. More details of this phenomenon may be revealed at a later date.''

It should be noted that the Prophet of Mercy would likely be transformed into a prophet form,as an infection form attacked and killed him.So, when the Master chief left High Charity, the flood must be using him also.