A fun combo deck I've been messing around with inspired by a Jesse Kotton video. Still working on the ratios, but so far this has worked the best for me. This is by no means a super competitive build and there are some big choke points in the full combo, but there are some back up options if you're stopped. I'm also not a competitive player, just a casual on ladder. Also the deck is expensive and is not budget friendly.
Card Explanations:
Prisma/A Hero Lives (AHL)/E-Call: Heart and soul of the deck. This is your combo starter. You always want to see Prisma or a way into it. AHL is ideal, but normal summoning it works fine, it's just riskier.
Souls Package (Souls/IOC/Prep): I use three of each for this because you always want to see some way into souls for full combo w/ Prisma. If you don't you can still end on Sprind, Schism, Granguignol, and a token, but you don't get the double bounce with Sprind/Sargas or the omni from Regulus. Illusion of Chaos shuffle back into the deck comes up quite often for cards you don't want to draw (O-Lion, Regulus, Schism). This package also works pretty well as hand trap bait. If you're going second, you can make Anima with Souls and potentially steal a card if you are trying to break a board, but feel free to cut Anima if you'd like to try something else.
Scareclaw/Starfrost Package: Your combo engine. Gets you into Cross-Sheep, Proxy F Magician, and Astraloud. You can also always fall back into a Baronne and grab Twinsaw in certain situations. (See combo below)
Cartesia/Granguignol/Luluwalilith: Cartesia is your second Prisma target. Make Granguignol w/ 2nd Prisma + Souls to send Apkellone and add Schism. You can cheat Luluwalilith out with Granguignol on your opponents turn to get an extra monster negate. Also if you have Cartesia + any way into Souls but no Prisma, you can still get into Granguignol for a Winda play. *Note: You will have to detach Granguignol from Sargas if you XYZ'd before you can summon Lulu.*
Shaddoll Package/Selene: Here to make Winda on your opponents turn. You will normally use this to make your Sprind/Sargas bounces live on Winda summon, so be careful not to use this right away if you can avoid it. Winda summon can also make your Lulu negate live on summon if there is a target for it. Winda also works well as a material for Selene on follow up who can summon back any Spellcaster (Granguignol/Souls/Cartesia) and then link into Accesscode. If you get to Accesscode you should probably be OTK'ing as you'll have 5300 ATK and 4 Links in grave to use for its effect.
Sprind/Sargas/Regulus/O-Lion: Sargas adds you Regulus while Sprind sends O-lion to GY. This gives you an omninegate on top of Sprind detaching a material from Sargas to bounce, which in turn activates Sargas to bounce/destroy another card.
ROTA: Extra search for Prisma or Reicheart.
Hand Traps: Ash is usually a must in MasterDuel as we all know, but I have left out Maxx C (if Konami is reading this, BAN MAXX C) since the deck is 45 cards already, feel free to add this if you'd like. I have yet to mess with a 60 card version of this deck because the deck relies highly on a consistent 2-card combo, but may try it for extra non-engine. Veiler is a must in my opinion as it can be used as a normal summon to make Granguignol if you don't see Souls and have AHL to still make full combo. Imperm is here to dodge Triple Tac/Thrust. I've contemplated adding Droll here as well due to Mannadium/Superheavy. Called by the Grave is must for the occasional Ash/Maxx C negate. You could also add Crossout, but I felt it was not at full potential without Maxx C or Droll.
This deck wants to go 1st. Some effects, such as Astraloud's can be used when going 2nd, but I have skipped those in the below combo.
Full Combo: Special summon Souls> Normal summon Prisma > send Visas to GY> make Lightheart> add/activate Planet> add/summon Reicheart > add Arrival > make Cross Sheep > activate Arrival > summon Visas > activate Lightheart GY effect > summon Light heart > make Proxy F > Special Astraloud by banishing Visas/Reicheart > Cross Sheep effect to summon back Prisma. *Note: It is important to make Cross Sheep BEFORE using Arrival as most of the time if you have summoned Souls, Cross Sheep will be your 5th summon. Holding Arrival allows you to play through Nibiru, however it won't be full combo.*
Second half of combo: use 2nd Prisma effect > send Cartesia to GY > activate Proxy F effect to fuse > make Granguignol (with Souls & Prisma) > send Apkellone to GY > add Schism > overlay Granguignol and Astraloud for Sargas > make Sprind w/ Sheep & Proxy F > send O-Lion to GY w/ Sprind effect > add Regulus by Sargas effect > special summon Regulus using O-lion in the GY. *Note: The O-lion token is not necessary for any part of the combo so feel free to skip its summon, but keeping it in defense w/ Planet on the field can give you an extra pop on follow up. Also feel free to use Souls effect before fusing it off to send Planet to the GY for a draw. This can sometimes net you an added Hand Trap, but you lose out on the follow up pop.*
Your endboard should look like this: Sprind (Bounce), Sargas (Bounce/Destroy), Schism (>Winda (SS floodgate)), Regulus (Omni), & a token. You should also have Granguignol's effect to summon Lulu (monster negate) once you've detached from Sargas for his effect. Also, ALWAYS PLAY YOUR MONSTERS IN DEFENSE ON TURN 1 EXCEPT WINDA. Winda is the exception because you don't want your opponent to just run her over with their normal summon. This will protect you from board wipes and will make your Planet live at the start of your next turn.
On followup: If your board is relatively unscathed at the end of your opponents turn, you can simply link into Selene w/ Sprind+Winda, bring back a Spellcaster w/ Selene's effect, and link into Accesscode for game. *Note: you should usually make Selene w/ Winda or Winda's effect will stop you from making Accesscode! Also Winda can only attack other monsters, so she is no good anyway if you're attacking for game unless there is a monster on your opponents field.
Other Techs: This combo can end on a plethora of other things as well, so experiment as you like. I've used Draglubion + Heart Earth (w/ Barian Shark attached) to rank up into Ultimate Falcon, Desavewurm (GY) + Avramax + Hope Harbinger, Sprind + Hope Harbinger, and a more Branded heavy package in different builds of the deck and I'm sure there are other ways it could combo forever, but there are only so many ED spaces. I also cut a small Dogmatika package to reduce bricking, but Ecclesia could theoretically be added off of Lulu if your opponent outs it or summoned off of Granguignol instead of Lulu, which in turn would add you Fleur de Lis. This felt a bit unnecessary to me, but it's there if you want it.
Overall the deck is relatively fragile yet fun and doesn't necessarily FTK, but gets pretty close. Hope you enjoy!