The attempt to transcend the second mortal coil is very dangerous. Starting the process is very easy. Ending the process, on the other hand, is very difficult. And ending the process successfully can be impossible for many people to manage.
For many people that attempt the process of advancing to the third mortal coil, the main difficulty lies in being able to remain alive while the life seed evolves and splits itself into two.
Taking his own advancement for instance, his life seed assimilated most of his internal organs, including his heart and lungs. Then his life seed split into two after becoming saturated with mass and potential.
If, for one reason or another, his life seed couldn't complete the process of splitting into two and failed in the process, he would have been left without a heart, his lungs, and many other organs.
That kind of situation will only lead to certain death. Nothing can help the life seed to split safely into the two if it doesn't have the potential to. But it is not the only cause of death during the process.
Even if everything was going well, the life of the cultivator will still be at risk during the process of the life seed splitting.
While the life seed is splitting into two, the cultivator will be without a functioning heart and lungs for a while. If they can't withstand this organ deprivation and survive until the life seed is done splitting, they will die and therefore fail to advance.
This sort of death is the one that can be avoided and influenced. As long as a cultivator is young enough, has strong reserves of life energy, and has life preservation pills, they will be able to survive the absence of their hearts and lungs and wait until the whole process is done.
This stage is what Lady Vena needs help with. She is over 70 years old, so she is by no means young. She is already this old even though she hasn't reached the peak of the second mortal coil yet. So she is lacking the inherent vitality granted by age.
If she is to survive the lack of a heart and lungs, she has to prepare very well. She has to prepare to the extent that the process of her life seed evolving and splitting doesn't take much time.
That is if the process starts at all. If her life seed never becomes saturated with potential and decides to evolve, she will just fail to advance, but she will keep her life.
Failing to start the process is better than starting the process but failing to complete it. In the case that she manages to begin the process of splitting her life seed into two, then she has to be prepared to complete the process quickly, or her life will be in danger.
She also has to prepare life-preserving pills in order to withstand the absence of her heart and lungs. Only in this way will she be able to survive the process.
Arthur believes that her chances of success are not high, but he still helped her prepare because she had helped him prepare for the regional sect examination and because he wanted a cultivator at the third mortal coil to be the one managing his dojos.
He doesn't need the manager of his dojos to be a cultivator at the third mortal coil because everyone knows that the Red Dojo is backed by a disciple of the Blood Skull sect. But it will be great if his manager isn't weak.
There is also the fact that the support he sent her was ultimately a drop in the bucket of his wealth. It didn't hurt him to help her, so he didn't mind doing so.
This also meant that he wouldn't mind it if she failed. At most, he would think that it was a pity that she failed.
Her death will count more towards the loss of a capable manager for his dojo rather than the loss of some money. This is why it was more prudent to help her by improving her chances of surviving the process of advancement.
However, even if she survives the process and succeeds, he doesn't think that she has any hope of reaching the fourth mortal coil in her life. In fact, he doesn't even believe that she can reach the fourth transformation of the third mortal coil.
He believes that she will stop at the third transformation of the third mortal coil because her potential will already be exhausted by the time she reaches the third mortal coil and because the difficulty of completing each level of transformation in the third mortal coil is exponentially greater than the difficulty of the process of advancing to the third mortal coil.
If the stress on the body for a single life seed to split into two safely and advance to the first transformation of the third mortal coil is already enough to kill the cultivator, it is unlikely that they will survive the process of splitting the two life seeds into two in order to advance to the second transformation of the third mortal coil.
At the second transformation, the number of life seeds in the body becomes four. Those four life seeds need to split into eight in order to advance to the third transformation.
So if she is to advance to the fourth transformation of the third mortal coil, the difficulty of the process will be eight times that of transcending the second mortal coil in the first place.
This high difficulty is one of the reasons why he doesn't believe that she can reach the fourth transformation of the third mortal coil. He believes that he has the right to make that kind of judgement because of the experience he has had enduring the difficulty of transforming his life seeds.
He is currently at the ninth transformation of the third mortal coil with 512 life seeds within him. Each life seed is a violet ball of energy that has the potential to be violent but is currently tame.