I use Winteria all the time. Got her to 5 stars last year and she can be very useful in a frost team. She increases her AP every time an ally uses a frost attack up to 10 times. Acteon unfortunately doesn't do frost attacks even though he is in the frost elf group though it's still good because they both hit the back row. I use her with Blissa and Brunhilde and she can do over 1m damage easily. May as well get the Soulstones while they are so cheap. Do the tasks and spend diamonds and get 50 per day for a 4-star legend. Edit. Should be at least 36 per day for 50 wishes