which shall i choose => END or DEX?

[Lafieru]

I'm sure you won't have a good evasion even if you put all your points into DEX - if you're main goal is staying alive, definitely go END, because it raises DEF, gives more HP, AND ups shield block.

DEX might be useful in helping to hit mobs if you like to solo reds a lot, but even then, I think it's more useful to pump END and use items to raise DEX.