Monster SOULs

A Monster SOUL is the very essence of a monster, it cannot have any traits and are always an up-side version of a Human Soul, and they are always white. The weapons can be everything. From Toriel's fireballs to Asriel's powers, as an example.

Trivia

 * It is unknown why Monsters can't have Traits, but it may be because Monsters are made only of magic and dust, and they are different from humans in terms of body composals.