Alas, there does seem to be a fair amount of missions that require a specific emoji. Right now, I have two (one that requires Captain Hook and one that required Prince Philip). I've had that one...I usually use Mickey (or some other emoji that gives lightning bolts) or Jiminy (that gives a star). Then I wait until the star and lightning are together in a place where I can use them together just at the start of blitz mode. That is the only way I've been able to get to 21 in blitz mode. (Same system works for the x suns in one game or similar missions.) I play pretty intensely until I get the emoji, then I taper off. I try to save the stars to use with the flamingos to get more.