The specifics on Magic, Relics and Artifacts are very confusing at first. So I thought of clarifying them so that people can understand it easily later on when it gets complicated.
Magic is mysterious phenomenon that occurs when one gathers and shape magical power into a given form.
There are many mediums of doing so such as the Power of Words; which is pretty self explanatory and a common trope in literature.
By condensing magical energy someplace such as their hands, or more rather by emitting it out into the air, then the next step is to chant out a word whilst maintaining a mental image of how the effect should work.
Of course one must visualise the correct word or phrase associated as some words could sound the same but have completely different meanings, in other words homonyms.
An example would be: 'Break through the limits, and exceed beyond the boundary.' This would sound like a typical Limit Break spell, but replace Exceed with Accede and you have a spell that makes absolutely no sense, well that or an domain controlling spell.
There are more mediums but that will be for another day.
In the world of [Revival Of The Choir] Magical Power/Energy assumes many names; Mana, Magical Power, The Power, Spiritual Trace, Nature's Grace, but the MC will call it something else, but for the sake of not spoiling you I'll just let you speculate on this yourself.
Now onto that ranking list.
Artifacts are items created by mankind, while Relics are objects that are considered, forbidden, 'lost' or forgotten.
They are often discovered in ruins of extinct civilisations, either being created by them or by another party.
These two terms are just to classify them and are actually not exclusive to just small handheld objects by the way, they can also be entire cities and even weapons of mass destruction like a Nuclear Bomb.
Under the Artifacts Category.
Mythos Tool: Formed through the association with an item and a legend. The more people believe in the said object, the more mental energy is being converted into the actual thing, e.g. El Dorado.
Treasures: Created by conventional and logical means, Treasures are the most commonplace of all Artifacts. They contain great power and they do not even need to have a magical nature to be considered as a Treasure, e.g. Guns, (only in other Worlds where they don't exist though).
Special Items: Similar to a Treasure, Special Items do not need to be of a Magical Nature. But they do rely on a supernatural power, most Special Items are created through unorthodox and illogical ways such as quenching the metal in poisonous substances, (how that works? I have no idea).
Unique Items: Rarest of the four types, Unique Items are created through unnatural means, powered by supernatural powers Unique Items are versatile in that they do not need the exact power source to activate it and that anyone, even normal humans could use them. But as there is no such thing as a free lunch it still drains a form of energy from the user as a consequence, typically Lifespan or just burning through a lot of calories.
Relics.
World Items: Relics that can upset a world's balance of power. Are considered forbidden, but are actually used discreetly by the upper echelons of society in other worlds.
Tsukumogami: Objects that have obtained sentience as well as a spirit usually resulting in them having humanoid forms.
Mysterious Wonder: Items of power with unknown origins and are typically found in ruins of ancient civilisations, some of the technology they have are so advanced that it is nearly indistinguishable to magic.
Netherworld Accessory: Items, typically jewellery and the like, that originate from the Netherworld, home of the Devils. They carry immense Negative magical energy that corrupts other beings and are the only way to obtain Forbidden Magic.