-Give tornado a fatty immolation for units, make it not channeled, and make it last ~10 seconds.
-Give mana shield a passive 4/7/10 intelligence for the naga in addition to what it does currently
-Do not buff destroyers. The problem with them is they are so good that you frequently get them even when there is zero caster to counter. They obviously lose value later on, and buffing them is the wrong mindset at fixing whatever problem you are thinking of.
-Reanimate dead needs a mechanic / rework change, but a band-aid solution would be to reduce mana to like 40.
-Hex is annoying for the non-Orc, but it's XP denial is still rich-content even if likely unintended. However imo, they should change it so that the nearby hero that isn't hexed gets full experience. Right now the hexed hero gets no XP, and not only gets no XP, but still acts like a hero nearby resulting in your other nearby hero getting only 50% XP.