Big Bang or Ifrit

I am currently lvl 164 with 2 SP left over and I dont know what skill to choose from the two. I currently have Max Para,Eruption,infinity,buff mastery and Arcane's Aim with all the one pointers. So I cant decide if I want Ifrit or Big Bang.
My reason for wanting Big Bang is for a longer DoT time so I can Bigbang>eruption>paralyze spam>eruption again without worrying if the Bigbang DoT timed out. As it normally does either rightbefore or right after the eruption.

But Im also thinking of getting Ifrit So that I can actually keep him summoned. (lol 20second timer). But the reason I want Ifrit is for the % resistence that it adds. because I feel it only works when it summoned (CURSE YOU NEXON FOR REMOVING MY ELEMENTAL RESISTANCE!!)

So im not sure which one I should get. And I dont do the whole max both at the same time. 1 good skill is better than 2 half assed ones.

Edit: relized that this should go in ask magican thread. So If a Mod could close this that would be appreciated.

Leave Ifrit unmaxed. It attacks far too slow to increase DPS by anything significant and the damage increments that it goes up by per level are very tiny.
Maxing Big Bang means more DoT.

Or, you can get Leafre set/Empress set/anything else that gives +1 All Skills and almost max both of them.

They are both not crucial but maxed Big Bang seems to be slightly more useful than maxed Ifrit for end-game bossing. I think it's too early for you to think about Ifrit versus BB now though. At this point, I think it would be the wisest choice to raise MW, Hero's Will, and Meteor before the others.