1 of the many strong decks in the new BP04 format! This deck utilizes the [Necrocharge] ability. For those of you who are unfamiliar with Nightmare (Abysscraft), [Necrocharge] effects can be used based on a specific amount of cards in your GY, similar to [Spellcharge].
Early Game: You focus on setting up your Graveyard (Cemetary) with"Emperor's Authority", "Spartoi Seargent", "Seeking the Pearl", and "Bone Chimera". "Soul Conversion" helps you gain value by popping your own "Bellringer" and "Seeking the Pearl" for 2 draws and additional value. "Bellringer Angel" and "Undying Resentment" help slow down your opponent and give you time to set up. "Emperor's Authority" can also add back Undead (Deceased) followers back to hand from your GY which is really helpful mid-late game.
Mid-Game: "Maruzensky" and "Soul Dealer" are great cards for slowing down your opponent by clearing their board/weakening their followers. "Playful Necromancer" is a good aggro card that can be combo'd with "Soul Conversion" for draws. "Cerberus" is really good for giving you a set up for your end game and/or for clearing your opponent's followers.
Late Game: Utilize "Alucard" and "The Order of the Black Knight's Supreme, Lelouch" combo'd with "Lesser Mummy" for powerful offensive [Storm] pushes. "Death's Breath" can help you play your Alucard or Lelouch for a cheaper cost while giving them Ward for extra defense. Cerberus' ability to place up to 2 "Coco" in your EX Area is helpful to give your Lesser Mummy's/"Alucard extra damage. You can normally deal 8-12 [Storm] Damage with the Lelouch + 2 Lesser Mummy combo and you could even deal 16 damage if you have 2 "Coco" in your EX Area.
Cards you could consider playing: Scorpius is a nice 2 PP follower with bane that can help clear wards/high defensive followers on Lelouch turn. Odile is alright imo and doesn't fulfill a good role in this deck; however, Odile is quite strong at NC 20 which is usually on Turn 8-10 depending on how well you fill your graveyard. Azazel can be really strong since it's a 4 PP follower when you hit NC 10, acts as a strong bane target that can rip a card from your opponent's hand, and on evolve, can make you and your opponent's defense become 10. This helps you get in range for Lelouch turn/Alucard.