Also,Gabriel Belmont is a merger of both Vlad II(The nickname "Dracul",how he dies as a human,starting off as a crusader) and Vlad III(His physical appearance,vampirization and brutal,misanthropic nature).
Mathias Cronqvist was a retcon because Konami was being funded by the Romanian government under Ceausescu who wouldn`t allow a national hero like Vlad Tepes to be directly depicted as an antagonist! Obviously,by the time the Netflix series came around the Ceausescu government was no longer in power and so whilst the Romanian people still regard Vlad as a national hero,the fact that Netflix is a private platform gave them greater creative freedom to depict Vlad Tepes as the vampire directly!
No sorry. The series is following the game timeline. Hence why you see leon belmonts portrait in the belmont home, and the story of leon searching for dracula/mathias after he disappeared and betrayed leon. Not only that but the characters hector and issac are in the sequel of the game that the anime is based off of. The series being based off of castlevania 3 and the sequel to 3 was curse of darkness which has hector and issac in it. The devil forgemasters. It seems season 3 will be based off of curse of darkness. Those hints you saw of the impaled bodies is something that Mathias did when he and leon belmont fought in the crusades together. A trait that he carried over as his new identity vlad tepes dracula.
ok in the center we have gabriel belmont who would become dracula or dracul, to the left we have vlad tepish dracula, aka mathias cronqvist, and on the right we have the same person, just with white hair due to a new body or something.
the thing is though, the people behind the netflix series did their research. Dracula is coming back. either every 100 years, or in curse of darkness's case which season 3 is gonna be based on, by a sacrifice. The belmont clan is eternally fated to battle dracula till the end of time. so he does have his stone.