man, I died at vaal like 10 times with my lvl 30 duelist :c
how did you do it? what class and style?
worst thing was, I forgot to make a portal that one time, and I had to grind my way up again (I was lucky only the first level had been reset, phew). now I'm like paranoid parrot with them portals. you can never have enough of them!
Done it twice out of two times, first with a glass cannon kiting archer ranger by staying far and spamming attack (hitting him when he is outside of the screen with shift+lmb) and moving a lot. Also piercing and poison arrows helped not giving him a break. When he spawned minions, I spammed split arrow and took them down pretty easily. The minions refilled my potions giving me that extra edge I needed, and I killed him with no flasks left. (used
this build). I do not think I used any portals, maybe one, not sure.
The second time with a tanky templar spellcaster, using molten shell, fire penetration, shield charge and lightning shield, with the passive that reduces the resistance when you change attack damage types. With this one, I had to use my portal twice because I ran out of flasks. Do not remember my build.
In both cases, evade the lightning at all costs, and hit from far, or use shield charge to move out of his attacks and minimise the damage.
(all of this is in normal, I am not that far into cruel yet)
Personally the monsters I have struggled the most with are: Merveil with my archer (forgot to equip cold resist), the first time you meet the woman with both and the second brute (1hit me). I do not remember the names.