One nightmare of a sea angel. Attacks rapidly as opposed to Cli-One, and has a chance to slow your units. Can hit between ranges 400-1200, meaning that no normal meatshields can survive, and neither can Hacker Cat. In Clionel Ascendant, she forms a deadly synergy with Angelic Sleipnir, who has a range of 372 and can deal with cats that enter Clionel's weak spot.
When fighting Clionel, use close-ranged cats such as Awakened Bahamut Cat, Artist Cat and Guardian Gamereon, as almost everything gets outranged. Assassinlan Pasalan and a few others can barely outrange Clionel (1250 > 1200). Despite his minuscule attack damage of 5660 at level 30, he can at least help slow down the powerful supports such as Angelic Gory, given the player brings along sufficient meatshields.
Descending from the heavens to judge this decayed world, this is the Beginning and the End. A doting monster parent to be feared. Attacks with incredible range, allowing strikes to slip through to the rear lines...
*In each stage, there is strength magnification, the value of health and attack power varies due to this value.
Cruel Angel Clionel is quite literally a sea angel, a creature known for its grace, beauty and horror, seen in this video.
Cruel Angel Clionel's Japanese description is a reference to Neon Genesis Evangelion, specifically incorporating the wordplay from Episode 24:「最後のシ者」 The Beginning and the End. The specific borrowed term can be read in three different ways, either as envoy, casualty or on the water's edge. Presumably this enemy is all three at once.