Major Planar Races
by HåvardHere is a list of the Major Planar races and thoughts on what Spheres they could be linked to:
1 Aasimon / Angels ---- (Any positive)
2 Archons ---- (Matter)
3 Baatezu ---- (Nightmare Entropy)
4 Demodand (Gehreleth) ---- (Entropy)
5 Eladrin ---- (Energy)
6 Guardinals ---- (Time, Thought)
7 Inevitables ---- (Time)
8 Modrons --- (Time)
9 Rilmani ---- (Time, Thought)
10 Slaadi ------ (Limbo/Energy)
11 Tanar'ri ---- (Entropy)
12 Yugoloths ---- (Entropy, Nightmare Entropy)
The above is based mainly on alignments of the creatures' home planes, though distinguishing between Time and Thought still is a problem. I figured Inevitables and Modrons, should we want them fit better with Time (Clockwork-ish?) than Thought. The Rilmani ended up with Thought, though I don't know enough about them really.
I figured the Yugoloth, being Neutral Evil could serve both Entropy and Nightmare Entropy.