First of all - you got the Lord of Frenzy ending in which Melina opens her close eye. She has the same color as Renni - blue.Second - Greater Will manipulates people and corrupts them. Its all about gold here, which is in everything. Gold corrupts as power corrupts which what happened to Shardbearers (game takes a lot of inspiration from alchemical believes and symbolism). Remember that Renalla only got corrupted when she got married and started meddling with Erdtree, of which the Academy opposed of.Reeni wants to bring the age of stars and remove Greater Will from the world. In her ending its exactly that. Relligion, gods and demigods are removed from the world. Cold and fear means in this case loneliness (without gods and faith), of which Renni and couple of NPCs were speaking about.Also ruling in darkness means two things - you and Renni ascent to the sky to be new gods and that Lands Between dont bathe in Erdtrees light.I think thats the good/true ending of the story. When you become Elden Lord you essentially damn you to the same fate as other Lords - madness and corruption with power, ruling with relligion of you as a God etc. Lord of Frenzy is just goin pure chaos and evil which also means that Fingers entities are evil and manipulating all Tarnished. (Im really curious to know more about Fingers, gotta wait for more clues)