Anastar was not one of the original Celestials, instead he was created by the dark energy of the powerful Celestial Legion. Out of Legion's chaos came the need for War, something that Anastar would come to represent. Anastar became one of the most famous Celestials, prayed to by many of the most violent creatures from across the Galaxy. Anastar is not completely evil however, he can also be seen to represent warriors and to some extent, honour in battle. This means that he can also be worshipped by those training to be warriors or soldiers.
Like the other Celestials Anastar has the ability to take many different forms, however he is one of the Celestials that is least known to do this. He mainly appears, if at all outside the Celestial Realm, as a being clad in armour and ready for battle.
Anastar is not generally liked by the Celestials Gaia and R'tas simply because of the damage that war can cause to the galaxy. Gaia, being the Celestial of life, sees war as a curse amongst mortals and R'tas, being the Celestial of Order, sees it as a pointless endeavour.