What are the common themes in a 'dragon devouring mage novel'?

Kubei was just an ordinary pencil and button pusher working a day job, hating his boss and making horrible speeches when one day he fell asleep after pushing an all-nighter. When he woke up, he was bound to a chair, facing three creepy robed women and in a body way too young and way too weak to be his own. As he slowly came to, he realized that he was no longer in the same universe as he was before. He had teleported to the Kingdom of Helius, where an all-powerful church rules its lands and wages war against the elusive group known only as Mages. Armed with an incredibly cocky neural interface that just won’t shut up and his own sheer wit, our MC will find himself not just fighting to survive, but maybe even something bigger than himself.

In the myriad realms, legends rise and fall in the countless eras. Yan Zaizen, a frail youth with an unfortunate history, meets one of these legends. Will this change his common destiny to something greater? The story of a boy that just wants a peacefully lavish life with money, amazing food, and a beautiful woman to love. The story of the heavens that laughs at this.

Layn's life was relatively simple. Married to a princess, working as the top archmage of the country... Everything would be great if he never learned that his wife was actually cheating on him! Instead of getting his revenge, he put up with the humiliation. For three long years. Three long years he needed to prepare for what would go down in the annals of history as the greatest revenge ever! That is if his actions didn't aim at rewriting the history in the first place...

English is not my first language so please take care of me and if you find mistakes in it tell me I fix it as soon as possible. Max Winchester died due to an "accident" while reading the novel after his death he meet God who allowed him to travel through and do whatever he think best but on condition to make Protagonist's life miserable. He also gives him the strongest system [Netori system] that help him steal Protagonists Woman, Chances, Luck, etc Why does God want to make that Protagonist's life miserable? And why [Netori system] given to the max let's find out. (English will get better after chapter 38.) I don't own a book cover, I find it online, If creator wants me to change it just message me, I will remove it.

Being taken away of all his freedom, Noah was thrown into the jail accused of a murder he hadn't committed. This incident broke his personality permanently, getting out of the jail Noah started living as a shut-in giving up at everything.  Noah read novels as a mean to pass his time, while reading novels an particular novel caught his eyes, it's name was 'the hero of velveric fights the demon lord' 'It's a harem novel......' That was what Noah had thought in the beginning but, it all changed at the end of the novel.  'What the Hell's with this crazy novel!' The protagonist and all his harem members were killed and in the end the demon Lord took over the world.  It was then, after finishing reading the novel, Noah started coughing out blood and succumbed to his lung disease. Opening his eyes Noah found himself in a body of a 8 year old kid of the Melvix family which appeared in that crazy novel. He was known as the garbage of the Melvix family by all the knights and family members but that didn't matter to Noah. What matter is that- 'It's impossible to survive in the novel if you are not strong enough......' ********************************************** The cover used for this novel isn't mine. if you are owner of it and want to remove it please inform me.

Killed by a grim reaper, our MC, Hakai, meets with the God of Reincarnation and tells him that he has passed the Trial of Souls meaning that he will be granted 6 wishes and the choice of any universe to reincarnate into. With one of the wishes, he decides to be a dragon. ------------------------------------------------------------------- Current World: One Piece MC will be OP. Lemon scenes will appear ;)