Hmm. I don't hate Isael but it feels incomplete, like it's the ending of a longer name. Like the others below, I thought this said Israel at first. Either way, I don't think it seems "too feminine" and I don't know where that vibe would come from.
You may want to also consider Misael. I knew a young man with this name and I always thought it was very nice... he pronounced it similarly to how you are saying Isael, just with an M in front.