IMPORTANT FOR MOD AND MODPACK DEVELOPERS: THIS UPDATE REPLACES ALL DEATH KNIGHTS ATTRIBUTES WITH THEIR ETERNAL ATTRIBUTES EQUIVALENT E.G. death_knights:blood > eternal_attributes:blood
If you are referencing death knight's SpellSchoolRegistry class, then the spell schools will be redirected to Eternal Attributes, but for datapacks, you'll need to change the attribute and school ids to eternal_attributes:{school}.
This also allows seamless use of the Unholy and Blood powers without the need of depending on Death Knights, incase you're interested as a mod/datapack developer.

Мод Death Knights добавляет в Майнкрафт класс Рыцаря смерти с магией Крови, Нечестивости и Льда. Создавайте руническое оружие, броню и используйте заклинания. Часть серии RPG Series.