Ball Lightning and the tokens generated from Elemental Mastery. One says "beginning of the end step" the other says "beginning of the next end step". My question is what happens if these cards are used with Sundial of the Infinite. If I play ball lightning then activate the sundial, will I have to sacrifice the ball at the beginning of my opponents end step. The same question goes for the tokens generated from elemental mastery. My guess would be I would not have to sac the ball, but I would have to sac the tokens at the end of my opponent's turn. Why exactly? Is this simply because of the word NEXT. Please help explain.