Heroes 5.5 WarGame Edition - Tactical Edition.

I've already recolored it, more or less.
However, I'd gladly accept your more professional version.
As a basis for divine vengeance, I personally chose the Divine_Wrath icon; it seems like it should fit better with the Darkness theme, but it would also be interesting to see what it looks like with the original Vengeance icon.

The spells of the Seraphim and Shadow Witches will also be changed.
Instead of Divine Vengeance, the Seraphim will receive the Vampirism spell (for 4 rounds), and the Shadow Witches will receive Divine Vengeance instead of Vampirism.
The reason is that dark units should not have access to Light spells (even though Vampirism requires both Light and Darkness).