It attacks with its physical and Metal Cutter, the latter doing heavy damage to one or more targets. It should be taken out before the Rahu, the left arm, because of this. It is weak to Fire, so Fire-elemental spells work well. The easiest way to defeat Ketu is to summon Catoblepas at the beginning of battle, both Ketu and Rahu are not immune to Petrify.
[view·edit·purge]Ketu is the descending lunar node in Vedic, or Hindu astrology. After the head of Svarbhānu, an Asura, was cut off by the god Vishnu, his head and body joined with a snake to form 'Ketu', representing the body without a head, and Rahu, representing the head without a body.