NHF – new heroes for Heroes V 3.1.

89 - base for the Death Knight (90) - Black Knight

As I understand it, if the Death Knight is number 90, then number 89 is definitely free, just like the Yeti (114)? That is, just like in the case of the Yeti, it can also be used to add some kind of unit?

Added 5 minutes later
When the need arises to use more IDs, everyone suddenly remembers #114, but everyone seems to have forgotten about #89 - you might think that this ID cannot be used for some reason (hence the question arose).