Number 7 Lucky Straight  is rank 7  Xyz monster that was first seen in yu gi oh zexal  consuming other luck  but in real life  it precisely work  on rolling dice and increasing it attack by the number multiple by 700  you could roll tow tim and get the high results  also if  the  sum of rolls make 7 you could activate  1 of 3 effect  send all card on field to graveyard ,draw 3 card send 2 to graveyard or special a monster from hand or graveyard 

Summoning this card need three level 7 monster which is difficult to do in one turn but not impossible there is different combo to make that happen one of which is ‘’fog king’’ and ‘’inferno reckless summon’’Special summon ‘’fog king’’ at first by ‘’call of the hunted’’, ‘’monster reborn’’etc and then activate ‘’inferno reckless summon’’ to summon 2 more copy of ‘’fog king’’

 now Xyz summon ‘’ Number 7 Lucky Straight’’ afterwards activate rolling dice effect to develop an Otk by getting 6 result of the die making 4200 atk  power combine it with "Oni-Gami Combo" and make great hit to opponent life point especially if you clear the field by lucky effect to ensure that your opponent won't be able to stop the attacks.

To ensure getting 6 dice result beside own lucky by rolling twice use "Dice Re-Roll" to increase your chance of getting a high dice number. Also accomplishment  of  sum 7 dice result is  6/1, 4/3 and 5/2 Which  is  applicable and could come in three form increasing your chance of making great Otk turn