Both dramas have fantasy, supernatural elements brought into current day life and society, with multiple stories and characters that seek to recreate the warmth and closeness of a family.
Mystic Pop-Up Bar has a more positive tone overall, with more action scenes and comedy.

Both dramas are female-character driven, have a significant immersion in the legal world (Hyena more because it's about lawyers) and deal with dark greys. Having said that, the story feels much more fleshed out in Misty, the background and the characters are better explored.
Hyena feels like a very ambitious trial to deliver a 3D story, but only a few characters get to that level - the casting was amazing, the chemistry was off the charts, and not just for the OTP, but also for the support characters, this elevates the entire drama and makes it more entertaining.
Misty is more on the realistic side and overall a darker tone, and acting is also excellent.

To me, the similarity came from the puzzle-like mystery that we are presented with throughout the dramas, getting bit by bit, but wait...almost nothing is as it seems. We have unreliable narrators or witnesses, people who have certain interests at heart, or even if eeeeverybody knows who the culprit/s might be, all can be explained through a different lens or perspective, depends on who's writing the script and what gets presented to the larger public.
Both dramas are very dark in tone, and the nuances of grey are never more apparent than in those who we deem innocent or always protecting the weak.
Twists are present, both in the past and present and by far the cat-mouse race will keep you wondering either who is the (real?) killer or how can we catch him and/or prevent him from further doing any harm. Watch both and prove me wrong :-)