Well, first of all I should point out that Campione has more than just Greek to begin with; Verethragna and Melqart, for two examples. (Verethragna is Persian, Melqart was from... somewhere in the Pacific Islands' faiths..) DanMachi used all sorts of different mythos, and I believe Sora no Otoshimono used Roman alongside Greek. Devil Survivor 2 the Animation uses a large number of them, and the actual game, DS2 or DS2 Record Breaker for 3DS uses several more. Heck, even DxD uses multiple mythos in the later seasons.
Casual references to some mythos can be found nearly anywhere, for example Twin Star Exorcists, Aesthetica of a Rogue Hero, Dragonar Academy, Saijaku Muhai no Bahamut (Bahamut the Weakest Undefeated / Undefeated Bahamut Chronicle), Shingeki no Bahamut (Rage of Bahamut: Genesis), and even Sword Art Online contain ample references to different mythos.
As far as Manga or LNs that don't have Anime Adaptations, there are Magika: Swordsman and Summoner, Gleipnir (this one is a Very interesting spin on the whole concept of the meaning of Gleipnir..), and I believe Ubel Blatt all contain a few.
Now, you might not believe me on a few of these, but, let me point out that all those stereotypical names given to holyswords or some sort of powerful weapon, are generally stemmed from some mythos. (For example: Excalibur, Durandal, Gungnir, Gleipnir, Sleipnir, Aegis, Artemis, Icarus, Mistilteinn, Laevateinn, Brynhildr, Cerberus, Fenrir, Mjolnir - - All names commonly used in anime, and all refer to some part of a mythos.)
Excalibur: A holy sword that can cut through any wood or steel. Durandal: An "All-Purpose Excalibur" - It is said to be able to cut anything "of this world" Gungnir: Can't remember the backing of this one off the top of my head... It usually takes the form of a spear. Gleipnir: In Mythology, Gleipnir refers to the Collar and Chains that were able to successfully restrain Fenrir. Most commonly used to refer to bindings or power restrictors. The term "Gleipnir" means "The Open One". Sleipnir: The "Steed of the Gods", a beast capable of traveling at speeds unthinkable. Aegis: Also sometimes called "The Absolute Defense", Aegis is thought to be the strongest Shield ever made. Artemis: Forgot this one's backing, too, though it is generally used to refer to a weapon launching high-speed and/or high-accuracy Projectiles. Icarus: A tool that enables Flight, refers to the legend of Icarus, who glued wings made of Wax onto himself and was able to fly. Mistilteinn: I don't know all the details behind this one, but it was supposedly a Magic-infused melee weapon. Has been portrayed in various ways, including, but not limited to, Pikes / Spears, Swords, Axes, and even Chainsaws. Laevateinn: Again, don't know all the background, but this was supposedly a Demonic sword, imbued with the power of Chaos/Destruction, and Highly Potent Fire magic. Brynhildr: I believe this is also referred to as "Brunhild". Weapon with High Potency Wind magic. Often used to refer to Guns. Cerberus: The 3 headed Demon dog tasked with guarding the gates of Hell. The name "Cerberus" is given to anti-hacking firewalls, as well as tri-barrel weaponry. Fenrir: Basically a large, Demonic wolf, with extremely sharp fangs, it is said Fenrir can tear to shreds anything that gets in its way. Mjolnir: The legendary Hammer brandished by the god Thor, commonly known to use the attribute of Lightning / Thunder, however, it also has the ability to Seal away other gods if worst comes to worst.
As a student of ancient history, let me help you out there with some backgrounds:
Gungnir: The spear of Odin, crafted by dwarves. Artemis: Greek goddess of the hunt and moon (so archery and animals usually go together with her) Laevateinn: Kind of "made up" weapon written into a Norse poem by a translator. There is contention as to whether it is a sword or a magical staff.
Mistilteinn is the only one I've never heard of before, but that's probably because I don't know much about Iceland. I did a quick read and it's supposed to be some enchanted sword that was wielded by an undead king who killed a lot of men.
Brynhildr if i remeber correctly was not a weapon but a valkyrie altrough im not a 100% also on wikipedia there's information on all of the above altrough i should warn you that most myth specially the hellenic (ancient greeks) ones have multipel versions so don't give up because the info seems to contradict it self its normal