Weapon Hafts (fiery, icy etc)

What do these hafts (icy, fiery, shocking, ebon) actually do? For example, with a fiery haft, do you actually see anything visually when you use them? thanks

afaik they don't do anything visually different, only swords/axes I've seen do this are Firey Dragon Swords (the swords of fire) and the Chaos Axes (axes of pure light).

the dmg types/upgrades you're talking abou do different damage types. fire will deal fire damage, lightning lightning etc (they all have different names like Icy will generally deal cold). Some enemies will be stronger, or weaker aganist certain damage types.

They change the type of damage you do. For example, normally, a sword would do slashing and/or piercing dmg and there is armor against that. Change the damage type to fire and you are nolonger affected by that armor. Furthermore, there are various spells that will add to you damage if the type of damage you do matches what they are looking for.