Six_Guns
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Ryogun Belfegor
I hope it's not, something where the MC is left with just one of the love triangle plus the 2 if I remember correctly Astoria and Dafne, then possibly 4 or 5 will depend on the author, but I believe the author will be team luna instead of harem, which is a shame, there shouldn't even be a love trio in history if there's only going to be one with MC.
The lineage purification potion is in advanced alchemy, imagine Rias, Akeno, Koneco, they would be 10x stronger without training and would still lose their weakness to sacred energy by 20 to 25% Akeno would probably reach 50% or more approaching Lucifer original that had 60%