By the way, here is the description of the Divine Vengeance spell:
Deals magic damage to the selected enemy unit. The amount of damage depends on the number and level of creatures killed by it.
Effect at levels:
[None]: damage = X*(10+1*SP)
[Basic]: damage = X*(30+3*SP)
[Advanced]: damage = X*(40+4*SP)
[Expert]: damage = X*(60+6*SP)
where X is the square root of the sum of all creatures killed by the unit, multiplied by the level of the killed creatures.
And to top it off, here is the description of Freezing Cold:
Deals ice (Water) damage to the selected enemy stack. The affected unit receives (1+SP)*3% more physical damage in the next turn if the hero has the Chaos Magic skill, and (1+SP)*1% more physical damage if the hero does not have the Chaos Magic skill at all.
Effect at levels:
[None]: damage = 10+10*SP
[Basic]: damage = 14+14*SP
[Advanced]: damage = 15+15*SP
[Expert]: damage = 30+30*SP