do elin really need to have int after rb she dont have any int attaks so this isnt really need right or is it for her new skill or her rebirth skill

I don't think she needs int actually - all her attacks are strong-based.

There were some mentions about her rebirth skill being terra but well, it's not.

It's a quest skill which is not in current version yet

Well if U really believe that elin will terrafication for example mages...I won't tell U that she cant. But chance is low. U need luck xDD Sadly in this version we don't have pet "JobSkill" . Terra will be probably Elin's "JobSkill".
My elin has less than 40 points in int. I think best stats for elin is a lot of con and agi, less strong and wis than con and agi. int lower than 40 should be ok. xD
We can't forget that elin has 3 strong/attack based skills xD She gets 3rd after her rb<3

Ni <3 :3