why is my shadow oneshot by voudsoul so easily

So basically the problem is when I use my moveskill and it's on cooldown to dodge the first lightning beam the second one ALWAYS hits and stuns me long enough to make the second one kill me where I stand with no chance of living. I have beaten this boss over and over with every other class and with no defensive investment at the same level other classes A dodge the lightning beams easily and B don't get stunned so badly when they eventually do get hit when I mess up the dodge and C can take a full barrage of 3 zaps without dying. My shadow however gets stunned every time, can't move fast enough to dodge apparently and has no way to live. I can take it on at level 19 usually but here I am level 24 and still one-shot by the beams. I have tried taking off my chest piece to move faster I have 10% MS boots and I have quicksilver flasks in 2 slots and the beam hits em with all that nearly every time unless I use a dash of some kind to get out of the way. this is always the wall with every shadow I make and I don't know what I am doing wrong. I have 72% lightning resist also so it's not a lack of resists