Water:
Weak to Lightning, Plague
Strong against Fire, Earth
Resistant to Water, Wind
Resisted by Ice, Water
Neutral to/from Light, Shadow, Arcane, Nature
Earth
Weak to Water, Nature
Strong against Lightning, Arcane
Resistant to Earth, Fire
Resisted by Earth, Wind
Neutral to/from Ice, Plague, Shadow, Light
Shadow
Weak to Arcane, Light
Strong against Wind, Fire
Resistant to Shadow, Ice
Resisted by Shadow, Plague
Neutral to/from Earth, Water, Lightning, Nature
Wind
Weak to Shadow, Light
Strong against Lightning, Arcane
Resistant to Wind, Earth
Resisted by Wind, Water
Neutral to/from Ice, Nature, Plague, Fire
Light
Weak to Nature, Fire??
Strong against Shadow, Wind
Resistant to Light, Plague
Resisted by Light, Lightning
Neutral to/from Earth, Water, Ice, Arcane
Arcane
Weak to Earth, Wind
Strong against Shadow, Lightning
Resistant to Arcane, ??
Resisted by Arcane, ??
Neutral to/from Light, Water, Ice, Fire
Unknown: Nature, Plague
[edit] updated based on Undel's infos. ;)
[edit2] Plague seems like it does extra damage. Still need to find the second resistance.
[edit3] Starting to add Earth.
[edit4] Put down near final stats for water. I'm not sure about the wind resistance, but I'm definitely not resisting Nature. Might have to recheck those other 3 under Neutral.
[edit5] Starting Shadow.
[edit6] Adding to Shadow.
[edit7] Finishing Shadow, verified Water.
[edit8] Finished Earth by process of elimination.
[edit9] Fixed Shadow. :) ty Salv!
[edit10] Starting Wind and Light.
[edit11] Adding visual graph.
[edit12] Finishing Wind by process of elimination. Graph not yet updated. Also thanks for sticky. :D
[edit13] Adding Arcane and putting more info down for Light.
[edit14] So confused. Earth resisted Arcane, but that would make 3 resistances. auuuuuuuugh
[edit15] k something definitely changed. Arcane is SE vs. Arcane. Putting Not Sure for element vs. itself. Also changing this up and reviewing previous data. That text up there is no longer correct.
[edit16] Too many changes currently going on with the Coliseum. I'll wait to update this after things settle down. :P
[edit17] Adding a new version. Seems like elements are resisting themselves again! Some of this is still wrong though. Working on it.