Cloudstinger does air damage, so if you want benefits, you'll need a two handed air skills... I'm not sure wether this exists though...
The way you have to see it is this: When you get a weapon, it doesn't just show how much damage it does, but also what type of damage it does. You have standard ones like slashing, crushing or piercing, and you have less conventional ones like air, shadow or bone.
You have to find the correct skill to match your weapon. If you have "warrior two handed crushing level 5 damage", it will only affect weapons with crushing damage, so it wouldn't count for cloudstinger... or mudstinger... or wavestinger...
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