I usually get all my runes and bone charms right at the beginning of every mission so you can really upgrade your void powers. I would focus on upgrading your health and your strength powers and that should help you with the sword fighting. And for being spot just take your time running through the map and find all the ins and outs of places. Hopefully this helps.
If you have trouble with swords fighting use your crossbow or your pistol when it's too hard or if there is too many enemies. Buy the bend time power as early as possible and upgrade it. You can also upgrade your blink power to kick the enemies when you teleport and attack them directly, it can be really useful