If I have the {exquisite blood} {viskopa guildmage} combo going and an opponent swings at m for lethal regardless of how I block, can I launch into the combo by blocking with a life linker? In short do I win or does he?
If you take lethal combat damage, you will lose. When the game-state is checked upon damage, it will see you at zero or less life and the game is over. All triggers on the stack, such as your combo triggered by the lifelink, do not get the chance to go off.
If you can do something -before- taking lethal combat damage, like blocking with a first strike life-linker, or blocking in a way that you survive with 1 health, your combo will go off.