while cool, I believe fully that Melina is the GEQ, or whatever is left of her, her connection to the Rune of Death is undeniable.
I would say the Jesus figure is Miquella, but they are firmly the Lucifer figure, good and ill, with Mohg taking on the Satan imagery as the flipside.
I would say the person who takes on the Jesus archetype is likely Radagon himself, and is also the "Son of God and also part of God".
Marika come across both Pagan and Christian, and as does her entire religion, which is the point, she, and her religion, are almost quintessentially allegoric to the Holy Roman Empire, with her being a Pagan who crafted her own new Religion, also her great and hated enemy, the Horned Ones, are very Muslim in aesthetic, which prior to the DLC was one of the missing allegoric entities to make this fit.
Godwyn cannot reincarnate, he is representative of Buddhism, he "achieved enlightenment" and escaped Samsara, this is why he is a grotesque take on a Buddha Statue in depiction.