I am new but I have played some characters to about level 50. Many of them did not do well when I go to Elite mode. So I started reading build guides.
My favourite skill so far is Olexra Freeze. But when I read guides none of them use it in the build. Why is that and is there a build that uses it somewhere? Please show me a url to it.
You could take mammothhunter’s build and tweak it a bit to include OFF. I’m not sure how well it scales in damage in ultimate mode, but I’m sure you could make it happen.
OFF doesn’t scale well in Ultimate damage-wise. It’s my favorite too, along with Night’s Chill but neither of them are good for anything besides support after Elite.
Would love to be proven wrong though 
All my Arcanist builds use OFF either way.
The reason why no one uses it, because it cannot freeze bosses, they have too high freeze resistance, and so it cannot even apply the fire resistance reduction on them. And the toughest part of the game is not killing crowds, because any build can kill trash mobs, but effectively killing bosses, and the skill provides no help in this.
Thank you all for your answers. It helps to understand but it is very sad that such a cool skill is not worth using in the end of the game.
It was not clear to me at all that the fire resistance reduction was not happening just because the enemies were not frozen. It says enemies resistant to freeze effects will suffer a reduced duration. Seems to mean that the fire resistance effect will have a reduced duration.
If it is not happening at all i think it should be said in very clear way in the description. And that does no seem a good design and may be the reason the Olexra skill is not used in the end of the game? Just my thinking on it.
It’s worth using but not worth enough to put all of your effort to. As devs said Crowd Control should works on crowd, not boss.
No one use it as a primary skill because it works only on crowd. Anyway there is Calidor Tempest to use as surrounding dmg skill and some skills/proc can deal dmg like OFF does. You may focus in those instead.