A history of the many books in my universe

A story of a young boy who lost everything more like gave it up Monarch may have been defeated the miraculous are safe now but a bigger threat has come Y/N is a boy who sacrificed his entire family except his younger sister he made a pact with satan himself and he has the ability to summon demons of many kinds to serve him but he isnt entirely eveil he does sonetimes feel regret but people dont see him and the 'shadow' as the same Y/N appears nice but how wrong are they read to find out i dont own miraculous or any of its characters but i own Y/N and any other unique characters brought in

A medevial Fantasy book following the events of the demon Invasion of Miradia a world of elves fairies dragons giants humans and more but now the demons and their warlord no one knows his true name they just call him the conqueror have come to the world and they bring war and death with them. The orcs trolls most of the giants and dragons have sided with him while the other species are putting their differences aside. Powerful masks are worn by commanders of the invaders these masks grant great power. The defending armies leaders have agreed if they have any chance at beating the conqueror they need the masks. Will they succed stay and find out