Special Summon an "Evil Thorn" with a card such as "Seed of Deception" or "One for One" then use its effect and Tribute it to Special Summon two more from your deck. Finally, Normal Summon this card and use its effect to make itself and your 2 "Evil Thorns" Level 2. Overlay this card and the "Evil Thorns" to Xyz Summon "Number 96: Dark Mist".
Normal Summon this card after you special summon "Rainbow Dark Dragon", making any other monsters you control DARK, if they are not already, they will now count towards the power-up effect of "Rainbow Dark Dragon".
Special Summon "Hero Kid" thus activating its effect to summon up to 2 more from your deck. Then Summon this card to turn them all DARK & make them all Level 3. Then Xyz into "Number 34: Terror-Byte" or any Rank 3 Xyz Monster you have.