Since it's become apparent that "Blood" is the Witch's Element I've been taking a look at the Witch as a school of its own.
And I noticed a peculiar thing. Witchcraft appears to be, almost by design, directly contrary to every other school while almost parodying them at the same time...
The 18th level elemental spells all do monstrous damage over a huge swathe of area... and the 18th level witch spell makes you... invincible against all damage... with a ten minute cooldown.
The elemental 3 meter spells are all some form of status effect, the witch 3 meter spell is a damage/self heal.
The Witch summon isn't the Undead... (this is going to get confusing but bear with me). Notice how, outside of earth, Witches are the only spell school with multiple summons? More to the point they're very much alike.
This is because these spells are an extension of the Witches initial "Bloodletting" spell, doing the same form of damage.
The Witch's actual "summon" is destroy summoning.
I know it sounds wonky but consider it for a moment.