oh ok i didnt know if arachs 10% slow had some magical equation, didnt know it was as simple as -10% to ias. so if i have a 30IAS GT i need 2x 15/15 jewels
This would be an expensive mistake.
Read my previous post.
With a 30ias -30wsm claw, your 2nd os should be a facet (if rules allow) or just a good defensive stats jewel (res, life, mana, fhr, etc)