I just came to the realization of the price of magic given by the Outsider. It all started with that hand of Granny Rags (Vera Moray), which Paolo had in the second game. This hand started to "run" along the protagonist, and also the Outsider ones commented "Sometimes pieces of us linger long after we're gone", and I thought about the fact that magic, starting from the improvement of regeneration, gives the marked person true immortality. Granny Rags lived about 73 years, according to the artbook, records and dialogues, but aged very much and lost the condition, but continued to live until Corvo eventually canonically killed her.
Corvo himself feels very good for his 54. I've come to the conclusion that magic permeates the marked one at the cellular level and the entire state of a person depends on it. ChatGPT have supported my idea that magic maintains life in the body, unless the carrier is killed or gets sick with something incurable. so in the first case the hand continued to live even without the body (as if the marked hand is a point of maximum connection with the Void, like its source marked on the body), and in the second case the mark will slow down the dying process caused by illness, thereby causing severe pain and suffering to the person, as it was with Daud. the Chat formulated the description very well: "it does not relieve the weaknesses of the body, it just postpones their consequences". Corvo is visually old, but still capable, precisely because magic maintains his health and internal processes. the aging process does not stop, but its negative impact is slowed down, but if Corvo had become terminally ill, then the mark would most likely prolong his torment, but would not relieve him of it. moreover, if magic does not affect the psyche, it still could cause internal conflicts on the background of psychological exhaustion.
well, also I looked at one of the unreleased scenes for the first part, in which Daud was supposed to cut off Corvo's hand with the mark, and thereby breaking the connection with the Void, so obviously Corvo would be weakened. even mentioning the prologue to the second game, when Delilah tore off the mark, Corvo fell to his knees completely exhausted.
as a result, I remembered about amulets and suggested that it would be possible to additionally use amulets that improve regenerative abilities, and I came up with the idea that such an amulet could really be created like the cameo of Granny Rags. it means that Corvo would really live even longer and, perhaps, would age more slowly, but there is a big BUT… but if such a thing is made, he will become a hostage of magic (I mean even more than without such an amulet), he would have to cherish this thing as the apple of eye. and if some villain found out about this and took it as a target, then Corvo would have a hard time. if such an amulet could be destroyed, then Corvo would be overtaken by everything that magic was holding back. he could, for example, instantly go old and suffer, because magic has been supported everything in him and slowed down all processes as much as possible. actually, how did it happen with Vera Moray - she became vulnerable to death without cameo.
I also discussed (with the ChatGPT) the fact of aging in eternal life. so even assuming the absence of violent death or diseases, the body would gradually deteriorate from oldness until… what? until only a skeleton remained? until the marked person became completely feeble? this would bring suffering and a desire to finally die. or the body would completely stop moving, and then the person would slowly die of hunger and dehydration. horrible. it's hard to call such immortality a life. Granny Rags was already weak, and all she could do was use magic against the bandits.
this is simply the most terrible side of the coin that I discovered, and the marked ones simply do not suspect this, because the Outsider calls it a gift, without naming a price, and no one has returned from the Void to reveal such consequences (excluding Jessamine's soul, it's another interesting story. or maybe Billie Lurk). moreover, the marked souls are forever stuck in the Void and suffer from eternal wandering.
I don't know if anyone has dug so deep into philosophy. and yeah, I took Corvo as an example bc I'm addicted of him having a power and rescuing Emily in the D2 against the canon.