Also, are they both digitally drawn? I'm quite sure the first one is, but the second one looks like it was inked.
All in all, very well done.
My inspirations were Michael Whelan, Frank Frazetta, Boris Vallejo, Roger Dean, and Rodney Matthews. These were all popular artists, at the time.
These were Acrylic, and I used airbrush, for the sky gradients, in the Sentinels one.