Beelzebuth

Beelzebuth (暴食之王) is one of Rimuru Tempest's Ultimate Skills. It had been created from the Unique Skills Gluttony and Merciless during Rimuru's Harvest Festival.

Chant
In the name of Raphael, I command you Consume all the magicules within this barrier Do not leave a single fragment behind 

Skills

 * Predation (捕食): To absorb the target into the body. However, if the target is conscious, the success rate greatly decreases. The affected targets include organic matter, inorganic matter, skills, and magic. Like with Gluttony, it can be used at a range and can now even affect space itself. Can absorb at least as far as a whole city's worth of Magicules.
 * Stomach (胃袋): The target can be stored. Items produced can also be stored. Capacity has been greatly enhanced compared to Gluttony.
 * Mimicry (擬態): Replicate the target's appearance. The Skills and abilities used by the target can also be used. However, this depends on the successful analysis and acquisition of relative information regarding the target.
 * Isolation (隔離): Materials harmful or unnecessary for analysis can also be stored. They will be used to replace magic energy.
 * Rot (腐食):The ability to decompose the target in conjunction with Predation. Also the ability to add the abnormal condition of decomposition. There is a chance of acquiring an ability after consuming only a part of a target's body. However, the chance of that happening is less than consuming the whole body.
 * Soul Consumption (魂喰): The Skill is only able to be activated when the targets lose their will to resist. Once that condition is met, from that point on, at any time the holder wishes, the holder can reap the marked target's Soul, even if the target has recovered their will to life and fight in the meantime.
 * Food Chain (食物連鎖): The user can freely copy the prototypes of the Skills of any subordinates, while also enabling the user to grant subordinates any Skills they are compatible with. Furthermore, the user's Magicule levels also grow whenever the subordinates show any significant growth.

Trivia

 * Beelzebuth is another name for the Devil in Christianity.
 * In demonology, Beelzebuth is one of the seven princes of Hell, associated with the sin of gluttony.
 * While Merciless is said to have been "sacrificied" in order to promote Gluttony into Beelzebuth, it is still present as the Soul Consumption subskill of Beelzebuth.