Wyvern Rhadamanthys is a low-level DPS. It has been left far behind by many other DPS, but it can still be used in certain PvE instances. There is no point in investing skill books in this unit at present, but if you have many copies, it can still be used at a certain level.
With all skills at level 5, Rhadamanthys charges Ultimate Vigilance in 1 round and releases 3 Alert Waves dealing 110% P.DMG each to random targets. Thanks to Flaming Wings, every 3 critical hits from allies ignite a pair of wings, and with all 4 wings burning he automatically generates 12 additional Alert Waves. While charging, he gains 50% damage reduction and a 100% chance to gain charge when an ally is attacked or dies. He is also immune to death once during charging, and all enemies that attacked him take an additional 200% damage from the discharge.
Unfortunately, it requires a lot of skill books. If you got a lot of copies, you could try to build it, but currently, copies are used to raise stars and achieve pavilion bonuses.