In most cases, it will be difficult to play pirated games in any kind of online multiplayer system. This is because most multiplayer systems require you to log in with a licensed account and play on a developer-run server. Some games don’t, and in those cases, you often can play online with pirated software.
It’s hard to say that any one game is the most pay to win of all. Many mobile games are built on pay to win mechanics, and they often work in similar ways. When weighing popularity against the extremity of the pay to win mechanic, then some of the most pay to win games are the FIFA series and Raid Shadow Legends.