This monster is based on the mythological duke of hell, Beelzebub, also known as the "Lord of the Flies".
This monster is the LIGHT version of "Steelswarm Roach", after having joined the side of good, as seen in "Sacred Serpent's Wake". The fact that this is an "Evilswarm" Monster is ironic, since the other "Evilswarms" are evil, while this one is not.
This monster's name references the "Exciton", the electrically neutral state of an electron found in insulators and superconductors. These particles are formed by the absorption of photons by superconductive substances, and can transmit energy without also transporting an electrical charge.
Fittingly, this monster represents a "neutral" character formed by a DARK monster absorbing "photon energy" to transform.