Is it normal that about 40% of my dreams have to do with tornadoes?

Maybe in your dreams, they're protraying your dangerous, destructive side as a way of subconcious expression and way of relieving your inner anger and frustration. Dreaming of tornadoes can be your way of getting intone with these feelings as Tornadoes are both powerful and to some, enigmatic or beautiful. Many people are fascinated with them and study them.

I had a dream that I was in love with Satan but Satan was actually Gabriel/Dracula from Castlevania: Lords of Shadow 2. He gave me lots of great powers that I became tyrannical with and, in the end, he broke up with me saying, "Before you love me, you need to love yourself." O_o

take it easy on Oz, dorothy

To summarize, dreaming about tornadoes is your subconscious's way of working out problems you may be having, from extreme emotions or stress, to feeling overwhelmed, to dealing with changes in your waking life.
http://www.dreamdictionarynow.com/dreams-about-tornadoes/