What's the point of O - X Element up? Options

[Raijinili]

For example, Flamberg on Yggdra, or Ice Javelin on Durant.
There's only one time I've seen the item actually change element for the user on aggression, but it was on the enemy side and it was from no element to an element.

Is there really any point to equipping these items besides the stat gains?

[Raijinili]

I don't understand your question, but no item will change the element of a unit, it will only cause used elements to be stronger, or elements used against them to be weaker - depending on the effect. With the Ice Javelin and Flamberg they merely raise the power of your Ice and Fire-elemental attacks. Meaning, when you use a skill that has an element (Blizzard/Diamond Dust or Flame) or when you use aggressive tactics with a unit that activates that element during aggression (such as Nietzsche for the Ice Javelin).