"As long as you keep trying to become the certain victor, then I will give you my power as the Witch of Certainty." 
Lambdadelta, as the Witch of Certainty, believes that "Hard workers are rewarded", she is maybe to grant wishes to humans, but only if they are determined to make the wish come true.
Like Bernkastel, she also gets bored easily, and she always wants to have fun - even if it can sometimes come at the expense of others.