"That Six" or "Dice Re-Roll" can be used to increase the chances of rolling a desired result.
3, 4, and 5 can contribute to the Red-Eyes/Beelze OTK. If your opponent attacks with "Beelze of the Diabolic Dragons" while they control another Monster and you control a "Red-Eyes Flare Metal Dragon" that was Xyz Summoned with "Dragoncaller Magician"(Or if you control a Set "Shrink", if "Dragoncaller Magician" was not used), activate this card. If you roll a 3, change the attack target to "Red-Eyes", whose ATK will double during the Damage Step(Or Chain "Shrink" with "Roulette Spider" before applying the latter's effect). If you roll a 4, make "Beelze" attack the opponent's other Monster, (then attack "Beelze" with "Red-Eyes" on your next turn, if the destroyed Monster was in Defense Position). If you roll a 5, negate Beelze's attack and Burn your opponent. You have a 50% chance of triggering this deadly OTK if you use "Roulette Spider".