[Moru]

The main reason of using a VPN or VPS is that you keep using your normal IP for the stream and the game. Everything else (where the attacker can get your IP) you use the VPN/VPS for. This will not protect your chat or browsing from getting DDOSed but it WILL prevent the attacker from killing your stream and your game. The benefit with using a VPS is the much bigger bandwidth of the host company to soak up the DDOS trafic so you can stay online.

If he has a fixed IP this is too late for him, he needs to get a new IP for this to be useful.