Yes, Kyra can seem quite powerful solo. There will eventually be things that trip her up, as there are for pretty much every solo character. Wait until a barrier or a location has her make a Dexterity or Acrobatics check. That will not be fun. But solo, when she can use her power so freely to keep her cards in her deck and not be pressured by the timer, she will not be too afraid of simply using up all her cards.
I did quite well playing Kyra solo. I got cocky in an encounter with a Hill Giant in deck 2, rolled very poorly, and died. I realized after the fact that had I played Guidance on the check, I'd have automatically recharged it and had enough cards in my deck to draw up.
As solo characters in RotR go, I'm rather fond of Mirisel. She does have some weak points (the d4 int), but keeping a Sage around helps a bunch with that. While playing with 3-4 people it pays to specialize, when playing solo it is helpful to be a generalist and pick up allies/items/etc that help cover for your shortcomings (typically your d4 and sometimes d6 skills)
I also played Kyra solo in RotR. Although she starts strong, I later found that her d6 strength was limiting — you want more than 2d6 from a Blessing of Gorum. Eventually she suffered a critical constitution failure in AD4 and died at the hands of Mokmurian. If I tried again, I might hang on to a Holy Light as an alternative for combat.
