Of the three basic elements, Cold has the most powerful spells. This helps to make up for the fact that there really aren't many creatures weak to Cold outside Gurgu Volcano. Further, a lot of creatures (including all Undead) resist Cold, making it perhaps the least useful attack element. On the upside, ICEspells never share a spell level with other damaging spells, so you can often feel free to use those spell slots. You won't run into very many Cold attacks outside of the Ice Cave, but there's plenty of gear that protects against it anyway.
Of the three basic elements, Ice has the most powerful spells. This helps to make up for the fact that there really aren't many creatures weak to Ice outside Mt. Gulg. Further, a lot of creatures (including all Undead) resist Ice, making it perhaps the least useful attack element. On the upside, Icespells never share a spell level with other damaging spells, so you can often feel free to use them. You won't run into very many Ice attacks outside of the Ice Cavern, but there's plenty of gear that protects against it anyway.
Ice is second to Fire in terms of elemental importance. Many cold-blooded creatures, such as turtles and lizards, are vulnerable to Ice. More importantly, few of these creatures are vulnerable to anything else.
Ice tends to work well against lizards, birds, and other types of animals (especially those found in deserts), as well as Firemonsters like Bombs. Relatively few normal monsters resist Ice, making it a good go-to attack element in many battles.