So I've finally become a Circle 6 Magician, and I want to try out some powerful spells...

but where are they?

I have a few Army of Darkness and Firestorm scrolls, and I remember blowing a Shrink Monster spell back in chapter 1-2... but I've never even seen a Breath of Death or Wave of Death scroll.

Am I supposed to buy the skill to craft the rune then make it later in chapter 6? That's really weird if so...

This is all the info I could gather...

Army of Darkness (Karras, Nefarius, Milten)
- Lutero (1x), Karras (1x)

Breath of Death (Pyrokar, Nefarius, Milten)
- Gorax (1x)
- Irdorath, the room before Archol

Holy Missile (almanac in the secret library)
(you don't need a scroll)

Rain of Fire (Hyglas, Pyrokar, Nefarius, Milten)
- Salandril (1x), Zuris (1x), Gorax (1x)

Shrink Monster (Pyrokar, Nefarius, Milten)
- Zuris (1x)

Wave of Death (Pyrokar, Nefarius, Milten)
- Gorax (1x)
- Irdorath - the door with five pillars - adjacent room(s)
- Irdorath - the Black Magician hall - adjacent room(s)

Half the people (playing G2A KDF) says that Gorax sells one copy of the scrolls (after you've learned to make a rune from them), while the other half says he doesn't. Since I almost never buy scrolls from him, I (personally) don't know.