Fierce Cyclops is a sub-boss, found in a group of three on the 244th floor of Tartarus. The shadows impede the player's progress and must be beaten to proceed. After the Shadows are beaten, the Judgment Social Link will increase to level 8. The Fierce Cyclops also reappears as a normal enemy in the Adamah Block of Tartarus, between floors 237 to 261.
Taking Abaddon as a persona eliminates most of the threat from these guardians, provided it is at least level 73. A Bow, Spear, or the Sabazios weapon will also help deal damage to them normally.
Fierce Cyclops appears in B7F and B8F of the Secret Laboratory within the Midnight Channel. After being defeated, they may drop a Hard Thorn. Selling 10 Hard Thorns will unlock the Guard Rosary accessory for sale in the shop.
In Golden it appears from B5F to B8F. It may also drop Meteorite for trade at Shiroku Pub.