thanks i'm glad it helped :D
i have died ~15 times in arachnee fight :D it really depends on their starting position. you shouldn't try to fight them off, your objective is to reach that blue glyph on the other side of the map. The ones with 3 mp are the worst (in my opinion). There are 2 ways to reach the blue glyph: left and right. I advice you to pick the right one even though it seems longer, because first option is too wide and your enemies surround you quickly. But in second option there is only room for 1 arachnee. You have 3 spells. In first turn i used summoning spell and moved towards second way, other aracnhees will most likely try to reach it. In second turn i used the spell that gives you mp boost and kept running. once you pass the 1 square passage in second option you will most likely finish the fight.
I don't have a ss of the map unfortunately, i hope this helps ^_^