Multiattack. The monolith champion makes one Greatsword attack and one Slam attack.

Greatsword. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 18 (4d6 + 4) slashing damage plus 13 (3d8) cold damage or fire damage (the champion's choice). If the target is within a fey court or castle, the target must succeed on a DC 14 Charisma saving throw or become invisible, silent, and paralyzed for 1 minute, while an illusory version of the target under the champion's control remains visible and audible. The illusion shouts to the target's allies for a retreat or similar action. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself and destroying the illusory double on a success.

Slam. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) bludgeoning damage plus 13 (3d8) cold damage or fire damage (the champion's choice).