On 5/21, the Immortal Fortress Twitter account posted the following text and image...

Another scroll, with this handwritten clue: "An underlying meaning of the crests is something that you might be taught in school. Look to these spells and keep a level head; An av’rage mind’s your most important tool." #NoStoneUnturned - @immortal4tress, 5/21 @ 5:07PM

On 5/22, the Immortal Fortress Twitter account added a color scheme for the schools of magic...
While not all mages sort the schools into chromatic scales, it doth appear this train of thought’s the next step on our trail. #NoStoneUnturned - @immortal4tress, 5/22 @ 2:14PM
NOTE: The image is based on a color image found earlier on Reddit, but there was no confirmation that it was the correct color scheme until now.

Solution Edit

OK, this one might be a little complicated...

Each one of the above spells has a school of magic and a level. Based on the 5th Edition spell list, they are as follows:

Spell Name School Level
Enthrall Enchantment 2
Mind Spike Divination 2
Symbol Abjuration 7
Raise Dead Necromancy 5
Arcane Hand Evocation 5
Foresight Divination 9
Scrying Divination 5
Shapechange Transmutation 9
Wish Conjuration 9
Cloudkill Conjuration 5
Modify Memory Enchantment 5
Druid Grove Abjuration 6
Time Stop Transmutation 9
Vampiric Touch Necromancy 3
Arcane Eye Divination 4
Find the Path Divination 6
Crown of Stars Evocation 7
Control Weather Transmutation 8
Confusion Enchantment 4
Cure Wounds Evocation 1
Teleport Conjuration 7
Stoneskin Abjuration 4
True Seeing Divination 6
Bless Enchantment 1
Disintegrate Transmutation 6
Locate Creature Divination 4

Now, for each of the schools, you now have to look at the symbols on the eight crests, associating the color with the school as per the image shown above. Each symbol's crest has a certain number of highlights:

Color School Symbol Number of highlights
White Divination Horseshoe 2 (ends of shoe)
Black Necromancy Dot 2 (inner and outer)
Red Evocation Five-pointed star 5
Orange Conjuration Septagon 7
Yellow Enchantment Infinity symbol 2 (each part)
Green Transmutation Ten-pointed star 10
Blue Abjuration Water drop 1
Purple Illusion Celtic knot 4 (loops)

Now here's where it gets complicated... For each one of the above spell schools do the following:

  1. Get the total number of levels in the spell list, if any (Illusion has none)
  2. Get the number of highlights from the chart above
  3. Take the average of the numbers. For illusion there's only one number as there are no spells, so it itself is its own average. For the others, take the average of the two values (add them, divide by two).

So, for each school, the totals are:

Abjuration: 17 spell levels + 1 highlight = 18, divided by 2 = 9
Conjuration: 21 spell levels + 7 highlight = 28, divided by 2 = 14
Divination: 36 spell levels + 2 highlight = 38, divided by 2 = 19
Enchantment: 12 spell levels + 2 highlight = 14, divided by 2 = 7
Evocation: 13 spell levels + 5 highlight = 18, divided by 2 = 9
Illusion: 4 highlight = 4, take as-is = 4
Necromancy: 8 spell levels + 2 highlight = 10, divided by 2 = 5
Tramsutation: 32 spell levels + 10 highlight = 42, divided by 2 = 21
That gives you the following numbers:

9 14 19 7 9 4 5 21

Converting those to letters is:


Which is an anagram for: