ToME WikiThese are pretty nasty, but really quite straightforward.
- Emnate Cold / Emnate Fire: each replaces the other. In both cases, the character with the corruption permanently emnates a cloud effect of either cold or fire, doing 2*lvl damage, with an area of lvl/10 (round up), The upside is that the enemies die that much faster. The downside is that it becomes utterly impossible to get potions/scrolls off the ground (which one depends on which version you have, and fire will also destroy a fair amount of equipment), it becomes nearly impossible to have allies (if they get close and are not immune, they're suddenly not allies anymore) and the terrain around you has a deisconcerting tendency to turn into either lava or ice, depending. It also gets a lot harder to keep Yavanna happy, and there are difficulties with tree-walking.
To make them somewhat less nasty...
- include an elemental shield, breath weapon and/or intrinsic brand for the appropriate element.
- include lightning, acid, and/or poison versions (also mutually exclusive. Each is less nasty for one reason or another.)
- allow you to switch between ice and fire at will.
To make them somewhat *more* nasty, just have the stores that sell vulnerable items close for the duration (anything that sells potions for ice, anything that sells scrolls, staves, wooden weapons, leather armor...really, most anything for fire.)