1) Open your firewall before he shoots at you - he will use his powerfull nuke at first shoot and it will melt on your firewall
2) Turn on your bloody fan storm skill
3) Start to attack with Soul Departs Spear series and then heuksal spear series and then Ghost spear attack series
Repeat 3 - 4 as needed.
You can easily kill him this way

P.S. You can use snow shield but do not use more than 20% one or your mp will go down so low that you will not able to attack him
