What are good Champions for Late game, Even If you sucked early game. in other words if you died early game 2-4 times in 15 mins. Which champion can actually come back and get OP in late game
Actually Nasus can't make a come back. He isn't even late game anymore due to all the nerfs and his inability to stick to his target. Sure he does become arguable #1 late game duelist (eat it Fiora and Sated Yi!) However his late game team fighting is piss poor to which the enemy team can easily take advantage of. All he can do is split push and pray his team can distract and survive the opposing team long enough for him to decimate a lane. Which usually means free dragon and baron for the opponents.
I am sure there are others I left out. But those all do crazy dmg late game.
Nasus, Veigar and Vayne come to mind, as long as you can get a decent cs those three are near impossible to keep down after ~30 minutes. Others include the other hyper carry adcs (Trist, Jinx, Twitch and Kog). Mages that cone to mind are Karthus, Anivia, Cass and Azir. Zed and Kassadin are pretty strong later on. Any sated jungler as long as the deaths don't throw you too far behind as well.
The biggest trick to any of these is you need to know how to play them from behind without getting further behind. If you can't cs well on one of them from behind they won't be good late.
I feel like Jinx and Vayne can come back easily even if you're 2 or 3 kills ahead of them.
Then there are champions who were built for late-game. Anivia, for example, takes forever to get up to speed. Two of her core items 
both cost a lot and also require time/spell-use scaling. But late-game, she's godly. If you make it to late-game you can deal 800 or more damage to squishies with just R+E.
Same with Tahm Kench, actually. Since you'll be building HP and he scales so well with it, he keeps ramping up even after you finish leveling Q and W.
Ekko once he hits level six.
MOST ADCs have a chance to catch up later game even after giving away 3 kills, even though they are the best ones to easily steal kills and catch back up in no time.
some good scaling mages, just know how to snatch the opportunity to do something and remain useful.
just take a few kills and let the snowballing work.
great splitpushers. Irelia can go tanky and continue to shred and dive squishies.
And of course, almost all supports. Their utility alone are already OP if people followed up, of course.
Without a doubt one of the best come-from-behind champs.
I once had to suffer a 5v2 lane as Jinx. There were SO MANY ganks and repeated 5-man ganks that it was essentially a 5v2 lane in the truest sense of the word. In the very first real teamfight of the game, with only the pieces of an IE, picked up a penta and immediately went from less than 1 item to over 2 complete items.
