Do you have her costume? If so I think that should sway things in her favor. It looks like you’re a long way from having a level 29 mana troop, but that plus Isarnia’s maxed costume bonus make her a TEN tile charge. That’s average mana speed! Crazy.
The breakpoint for 11 tils is 10%. The costume plus a level 1 mana troop is enough.
Miky, miky and miky.
I choose her over Issy, magni, Finley.
And I did nothing wrong
She is my favorite except blue reflect and purple titans. 
My thoughts.
I want to thank everyone who took the time to reply to my post.
I doubt that many of you would agree with my choice, but my heart ruled my head and I went for Issy, there’s just something about her that I really like.
I know snipers are important but I have lots of snipers, GM, Marj, Sartana,Panther,Lianna, Kingston etc etc .
And hopefully if I get her costume she’ll be even better than she is now…I live in hope 
So thanks again
Marie
Awesome!! It’s your game so no need to defend your choice. If it makes you a happier gamer, then the choice was right for you.
Exactly. Hero leveling should be based on self preference / playing style and not by other’s influence.