Art

Arts (技術) are techniques performed entirely through the users own capabilities, rather than through the completely automatic process of Skills.

Battlewill
Battlewill (気闘法) is a family of arts that makes use of the fighting spirit present in all living things to perform powerful physical attacks and effects that resemble magic. Unlike magic, these techniques do not require any sort of chant and usually have little to no casting time. Examples of Battlewill include, but are not limited to, body and weapon strengthening, presence concealment, creating aura constructs, blocking an opponent's regenerative capabilities, and flight.

Hazy Style
The Hazy Style (朧流) is a family of sword skills intermingled with aura centric techniques. It was created by Byakuya Araki and passed down to his grandson Hakurou. This is the sword style used by most of the main characters in the series including Rimuru Tempest and Benimaru.

Magic
The phenomena known as Magic (魔法) can be in the form of a Skill or an Art. The process of chanting, gathering energy, and constructing a magic circle is an 'Art'. Magic performed as an art will always have a weaker sway over the worlds laws than magic performed by a skill.

Mystic-Arts
Mystic-Arts (妖術) are an advanced form of Arts that involve adding magical properties to one's own aura, essentially fusing Battlewill and Magic to create a technique that surpasses the potential of either individually. Attacks with Mystic Arts encompass both physical and magical phenomenon, allowing it to be effective on virtually any being given enough power. Basic uses of Mystic Arts include coating a sword with magic-infused Aura and hurling Aura with magical effects at someone (similar to Elemental Magic).

Phantasmal Style
The Phantasmal Style (幻影流) is a family of Arts created and used by Dino. Dino puts the illusory powers of Sloth-later Belphegor-into his sword to interfere with the senses and spirit of an opponent mid-battle.

Veldora-Style Killing Arts
The Veldora-Style Killing Arts (ヴェルドラ流闘殺法) are a family of arts created by Veldora Tempest while inside Rimuru's stomach. They were created by Veldora sorting through fictional techniques found within manga and recreating the ones he found useful.