Okay, well. There's magical objects, which are created through... a lot of ways really. Then there's alchemical devices, which are magical items created via alchemy Then there's conceptual weapons, which are very rare and include some incredibly scary things(for example, the Futsu no Mitama no Tsurugi is a conceptual weapon in this setting. It embodies the concept of death, and as such it is the absolute death of everything that kills even that which has no concept of death). Then there's blessed items, which are the result of the acts of a Saint or other high-ranking representative of a deity blessing an item to imbue it with holy power and enhance its capabilities, especially against vampires and demons(who are not in this RP as playable mostly because they tend to be pretty strong). Then there's holy items which are basically holy from the start and therefore more powerful...

The biggest one to bring up is Saint's Tools, since you mention Ascalon which is a Saint's Tool in this setting. Saint's Tools are items that only a Saint(basically a person chosen by a god of any religion) can wield. They are incredibly powerful and impossible for humans to create, though weaker replicas can be produced. Saint's Tools can range from things like Ascalon to in one notable case the Saint's own body. There's holy protection on Saint's Tools keeping them from being altered or changed in any way unless it is by something on their level or higher.

Holy Protection can be broken but that's by extreme levels of power that we won't be seeing in this RP(or the Futsu no Mitama). Not that we'll be seeing it in this RP. Or Saint's Tools, for that matter.

Basically, what would be possible for magi to create is magical items, which are very very versatile and come in a lot of different kinds.

... Hopefully that did not go on too long or get too complicated. ^^;