Could you perhaps give us some more ideas about silver keys? Or perhaps your own versions of the existing spirits, regardless of the key core?
Part 1 (be sure to check @yamacutiee‘s blog and art, she’s an amazing artist and I’ll always be grateful to her for blessing me with that beautiful art of Natsu and Lucy <3)
Gate of the Eagle, Aquila. Summons a bald eagle that uses Sound Magic to stun its opponents. Aquila is a very intelligent creature that often sees possibilities on the battlefield that its summoner doesn’t and acts on them on its own. This always results in its summoner’s side gaining an advantage over their opponent.
Gate of the Crow, Corvus. Summons a crow with one red and one black eye. Corvus uses his red eye to hypnotize his opponents and the black one to erase their most recent memories. It’s been said he has a human form, but rarely uses it, because usually the battle is decided the minute the opponent looks into his eyes.
Gate of the Water Serpent, Hydra. To summon this Spirit, the wizard has to be in an area containing water. Hydra is an ancient and proud spirit that uses powerful water spells against its opponents.
Gate of the Dragon, Ryuukyuu. Summons a young woman who uses Fire Magic in combat. If her summoner has enough magic power, she can transform into a relatively big fire-breathing dragon (smaller than the ones we know of, yet big enough to make her opponents tremble in fear).
Gate of the Fox, Vulpis. Summons a shapeshifting fox that uses Illusion Magic. Vulpis is extremely intelligent and is known for spending a lot of her time on Earthland, studying people’s cultures and traditions. Whenever she reaches a new level of knowledge and understanding of the world, she grows a new tail. It is said her full form will have nine tails. Currently, she’s on her 6th.