Love, hope, compassion... This is what people say monster SOULS are made of. But the absolute nature of a "SOUL" is unknown. After all, humans have proven their SOULs don't need these things to exist. But they will never know the joy of expressing themselves through magic.
~ A book from Undertale talking about Monster Souls
Monster Souls are currently the weakest soul in Glitchtale/Undertale. Monsters are naturally born with this soul.
Monster Souls appear as white upside-down hearts.
Like other souls, they seem to be glowing.
What Monster Souls Are Made Of
Monster souls are made out of love, hope, and compassion. Users of this soul have bodies mostly made out of magic, thus making them vulnerable to attacks from humans. Since their bodies are mostly made out of magic, they can have different weight, height etc. from their age.
Magic : The main ability of all monsters, a magical weapon can emerge, attack, or defend, each monster's magic is different.
Heal : Each monster has the ability to heal themselves or to heal others to fill max HP.
Blue or Orange attack : All monsters can use this ability, The user can send a blue or orange attack if it fights with an enemy, the blue attacks do not harm if enemy do not move, but blue attack do damage if enemy move, but orange attacks do damage if enemy do not move, but do not damage if enemy move.