Guide for a Mage/Kensai character

So A while back I found this guide for a Kensai/Mage that I saved: https://www.reddit.com/r/baldursgate/comments/cga9ua/deleted_by_user/ but now that I finally have some more free time to play I saw that the post had been deleted, which is a shame as it looked pretty good!

The only thing I remember was going to dual class Kensai into Mage at lvl 9, though I'm not sure why that was anymore. Could anyone tell me? And perhaps could anyone share some tips for this build? I love Gith like characters, so playing such a character in BG2 should be perfect for me! So perhaps someone could give tips or give a guide? I did hear that some of the necesarry weapons were pretty hard to find?