I, the villain, trained the loser into a dark boss

Will, a senior game planner, has a dream after he found himself the cannon fodder villain in the story of quitting the team - he wants to make all the losers chasing their husbands in the crematorium turn evil and torture the protagonist! He teaches the timid beast maid to imprison the one you love forever. He teaches the arrogant and venomous loli witch to make your loved one have only you in his eyes. He teaches the iceberg and cute half-elf princess to...