War God Advent is a really iffy card imo, and could sometimes become a dead draw, but that just me. Maybe put in something like Veiler, Maxx "C", or D.D. Crow, up to you.
The Extra deck could be changed ike Sylphine the Sub-Zero Siren, I know you can make out of Murakumo and Advent, but as of now, you don't have a way to Banish Murakumo from your grave and most of the time you want it in you hand. Why not a monster like Diamond Dire Wolf? Maybe put Constellar Omega at 2 and Paladius at 1.
Just suggestions, don't tak em to heart.