Welcome to the site, White Knight!
First, I'd like to direct your attention to GreyOwl's customization tools found
here. He has some great templates that will allow you to make your customs look very official.
Armist
For Enchanted Arrows Special Attack, 5 automatic skulls is incredibly powerful. That's equivilant to rolling 10 attack dice at range 6. I'm not specifically saying it's too powerful, but you should really increase his cost dramatically, if you want to keep it so strong.
For Missle Shield, official cards never describe what is happening in the power text. The description is always left in the power's name. Perhaps you can change the name to Magical Shield or something like that. Then, change the wording to: Opponent's figures must be adjacent to Armist, and all friendly figures adjacent to Armist, to attack them with a normal attack.
EDIT: Wow. Super-ninja by Mac122.