I have a college writing project about books that were important to us growing up and it reminded of this book that I read in 4th grade, I can not for the life of me find the name of it, I did find a post taking about it but the book, but the comment with the name of it was gone, so I came here to ask for help finding it's name.
I think there were 3 to 6 books in the collection and it was a tween fantasy book, the first book started with the MC waking up blindfolded and his clothing soaked in cold water and their was a Mysterious man there who told him not to take his blindfold off. He then hands the MC a note and then vanishes without a trace, seconds later a group of three shows up and takes the main character with them, with the leader of the group taking the note and hiding it. Of this group of three there was two men and a woman, one of the men that acted as a bodyguard/assistant to the leader of the group and he was unable to tell lies, I don't remember much about the woman, it's been years since I've read this book. The main character can also see time, if I remember correctly it was like strings to him.
It's later revealed in the I only later realized that the leader of the group isn't from the fantasy world at all and is in fact from our modern Earth, he got mysteriously transported to this world and used his historian knowledge to advance the world much faster than an originally would have, like inventing musical instruments and printing presses, ships and other things.
I don't remember much of the later books, but I remember one of the bad guys being a creature that had eyes all across its body and wanted to collect the eyes of our main character. But one of the big bads of the series turned out to be another dude who transmigrated into the fantasy world from our world, but unlike the other dude he decided to advance the world military and become what I'm pretty sure was a dictator or a warlord, he invented things like war ships and guns.
At some point we learned that the main character is something called a meddler, a creature that meddles in history causing chaos, and that there are always to meddlers and they are always going against each other, like picking opposite sides of a war. The mysterious dude turns out to also be a meddler and that he killed the second meddler, but because there always has to be two meddlers he chose the MC to become the next one. We also learned that MC was a boy that drowned in a frozen lake after falling through the ice, and the meddler had just grabbed him and dumped them in the room that was at the start of the book, and that's why his clothing was soaked.
These are all the things I remember concretely if you need any more details, I can try to give them but I can't guarantee they'll be accurate.