Regardless of Shapeshifting flippers or no, the time to regrow a severed appendage (like Benedict’s arm, or in HoC, Gerard’s legs) cannot be based on a multiple of the time it would take a mere mortal to regrow a similarly severed appendage. How do you determine healing abilities that are superhuman and the rate at which they occur.
Also, what is the condition of a half-healed severed arm? Bone? A tiny arm? An extended stub? A big chrysalis? I’m not sure I know what the intermediate steps would look like…
No way I could cover all this in comments…
Some terminology is really hashing this up. Healing at ‘normal’ rates in my examples is based entirely on the superhuman rates that are ‘normal’ to royals (gamewise). In theory, the mechanic is not based on mortal healing rates (but it is—since we have mortal as a baseline low and Corwin as a baseline high.) This is why ‘vanishing’ healing abilities from the steps as you decrease effective rank of Endurance works for me.
You are also asking, I think, how do I project a ‘normal rate’ for abilities that mortals don’t have? Reverse engineering is one method. Canon helps with this.
Super Endurance guy regrows eyes and nerves to make them work again in four years.
Mortals do not regrow nerves.
E16 regrows in four years.
I have seven step ranks between those two.
And the math (?) looks like this:
|E16||4 yrs (corwin)|
|E4||20 yrs (zero endurance)|
|E1|| 100 yrs (mortal endurance)|
without some extraordinary story value, the last two ranks do not regrow nerves at all.
There is much more to be said.
The regrowth is not about mass—it is about power and complexity. Corwin’s eyes are a complex and power-laced object to regrow. The eyes touch upon more Primal powers than any other part of the body. This does change by individual.
Handy to have eyes as a canon reference because most other things are easier than eyes.
IMC, Benedict’s arm is harder to regrow than his sibs. There are more Primal powers in the nature of Ben’s arm than say, Rinaldo, and so there is more to regrow.
IMC, Gerard’s limbs are harder to regrow than Corwin’s because of the same. They are metaphysically more complex.
As to the steps of physical regrowth, this would again depend on your metaphysic foundations. IMC, Corwin’s eyes would have restored physically as blood, then hunks of gel, then eyes, then working eyes, then supernormal (primal) working eyes.
IMC, Gerard’s legs (they are shattered and mashed, yes?) would restore as mashed, then cohesive hunks of mash, then knitted bones, then working muscles, then working legs, then supernormal (primal) working legs.
Just one of the meta-breaks with tech/magic healing of an amberite is that there is no better system for the primal healing of an amberite than an amberite’s own healing.
(But IMC, getting the healing jump-started with magic or tech is fine as long as you get an expert to help you or become an expert.)
So, for instance, if you blind Fiona with hot pokers, you are trashing the meta-links she has to arcane and primal perceptions. This didn’t hold Corwin back much, but it would add healing time to Fiona (even moreso because she doesn’t have anything like Corwin’s Endurance.)
Yes, she could get working eyes in about 20 years, but she still wouldn’t be able to see the hidden universe properly for another ten (next step on chart.)