I use Selenia sky as my default Summoners because I'm yet level my summoners who are still stuck on level one. She is able to make use of my level 4 Steem Monsters - the main challenge comes when i want to complete my daily Quests and I'm forced to use level One Summoners.
Its good seeing lots of people sponsoring tournamnets like this ones!
Yeah Selenia sky is awesome! Daily quests is easy when you have all high level cards :)