Shalom R' Avrahom,

I will try to respond to your questions regarding the different types of Kohanim and your other great questions.

The first type is the Kohen Gadol mentioned explicitly in the Pesukim regarding the appointing of the Kohen Gadol: anointed with the Shemen ha'Mishchah, dressed in the garments of the Kohen Gadol, and serving in the Mikdash in that role. Since the Torah states that the Kohen Gadol is uniquely anointed with oil upon his head, it is clear that when the Torah speaks, in the context of the Ir Miklat, about the murderer being allowed to leave upon the death of the Kohen Gadol, it refers specifically to such a Kohen Gadol as described in the verses.

However, after the Shemen ha'Mishchah was hidden away by King Yoshiyahu, there was no longer an anointing. Instead, a Kohen Gadol would assume his role merely by wearing the garments of the Kohen Gadol. Were it not for the Torah's explicit inclusion of such a case, one might have thought that only a Kohen Gadol anointed with oil qualifies according to the Torah's law. I would point out that since there is no clear or direct logical connection between the death of the Kohen Gadol and the release of the murderer from the Ir Miklat, it would have been reasonable to say that only what is strictly defined in the Torah as Kohen Gadol applies to the law of release.

I am aware that Chazal offer various reasons connecting the Kohen Gadol's death to the matter (for example, his responsibility for the generation), but these are not mentioned in the Torah itself and should be viewed as supplementary explanations rather than the core Torah law.

The third type is a Kohen Gadol who is actively serving but may be doing so as a replacement, either because the original Kohen Gadol is temporarily disqualified or because he has a permanent blemish preventing him from serving. In such cases, it is not obvious that the death of this acting Kohen Gadol would suffice to allow the accidental murderer to leave the Ir Miklat.

The fourth type is a Kohen Gadol sheʿAvar -- one who previously served as Kohen Gadol but no longer does so, either because the original Kohen Gadol recovered and returned to service, or for other reasons. Even in such a case, the Torah includes his death among those that allow the murderer to be released from the Ir Miklat.

Here I connect to your second question regarding the Sgan Kohen Gadol, the deputy Kohen Gadol, or a Kohen appointed to replace the Kohen Gadol in case he became Tamei. There is a general rule that one ascends in holiness but does not descend ("Maʿalin ba'Kodesh v'Ein Moridin"). Thus, even if a deputy was appointed only for a short time, once elevated he retains his status and is not considered to revert to an ordinary Kohen even when the actual Kohen Gadol returns to service. Therefore, because there is no intermediate level between a regular Kohen and a Kohen Gadol, and because of the principle that one does not lower a person from his sanctity, we are compelled to treat him as a Kohen Gadol, even if he is not actively serving. Since the Torah provides an additional, seemingly redundant verse, it allows for the inclusion of this category as well, since he too is, in a certain sense, a Kohen Gadol.

It is clear that we are referring to a Kohen who was appointed specifically to replace the Kohen Gadol in the event that he became Tamei, and indeed the Kohen Gadol became Tamei and the deputy served in his place, even if only for a short period. However, a Kohen who was merely appointed as a potential replacement but never actually needed to serve would certainly not cause the murderer to be released from the Ir Miklat upon his death.

As for your third question, I alluded to the answer at the beginning, but I will briefly restate it: since there is no clear and direct link between the Kohen Gadol and the murderer in the Torah itself, one might have said that if the verse ties the murderer's release specifically to the death of the Kohen Gadol, it applies only to the original type of Kohen Gadol, that is, one anointed with the Shemen ha'Mishchah. In such a case, it would be viewed as a unique Torah decree (Gezeiras ha'Kasuv), and without the anointing oil there no longer would be a mechanism for the murderer ever to leave the Ir Miklat.

Best Regards,

Aharon Steiner