Magic Items
Common items, especially weaponry, may be infused with magic through various means. The most common of this is to inscribe the tool with magical runes. The safest, most stable, is that used by the wizards of the settled nations - channeling magic through refined channels and imbued into precious metal that is then used to inscribe or ink the tool. Those of the Outer Gods use the stuff of raw magic, unfiltered, etched into the weapons in runes of the Dark Tongue, the twisted language of the immaterial realms. The most dangerous of all is to bind a demon within an object - this, too, uses the Dark Tongue, but the magic used holds the demon within the material world, drawing souls of those slain into the tool for sustenance.
In any case, the greatest limiting factor on the power of these tools remains to be physical space. The inscriptions must be marked on the surface thatis associated with the tool's use - scrolls and banners are marked on the parchment and linen, weapons upon the blade, and armour upon the surfaces turned to face the world. Daemon weapons are inscribed with binding in much the same fashion, though the surface could be said to be the demon's very form from that moment onwards (and is indeed just why the body must be thus bound). With weaponry, this presents an interesting conundrum, as the most effective weapons - spears and the like - often have very small striking heads. This renders them difficult to inscribe all but the most basic of magics upon, for such inscriptions require a great deal of text. While that is not to say that to do so is impossible - indeed, marrying the advantages of great weapons and powerful magic make the most powerful weapons of all - it does mean that the weapon of choice for carrying magic is the sword.