Which is more powerful?

[Kathos]

Originally Posted by Hento

Btw, does Battle Alchemy award only affect fire and poison used by specific units, not your spells?

+10% fire and poison damage
You would have to assume it affects all spells and effects coming from your hero/army. It doesn't specify creatures or spells.

[Hento]

But you can't see any increase in spell damages...

[DGDobrev]

The Battle alchemy medal provides an increase of the post-effects. For examlpe, the flaming arrow burning damage (if you get the post-effect) will increase. Poison Skull's poisoning damage (once again, provided you get it) will also increase.

[Kathos]

What he said, it seems as though the translation or wording is a bit misleading =)
- Battle Alchemy
Requirements: successfully ignite or poison an enemy troop
Level 1 - +10% to burning/poisoning post-effect damage / 50 successfully poisoned/burned enemy troops
Level 2 - +20% to burning/poisoning post-effect damage / 150 successfully poisoned/burned enemy troops
Level 3 - +30% to burning/poisoning post-effect damage / 400 successfully poisoned/burned enemy troops
From DGDobrev's info page.