What Vizkopa Guildmage in this case can do is one or two things. First of all, the Guildmage can give a creature lifelink until end of turn, which is an important part of the combo, although there are certainly other ways to do this. But when you do pull off the combo, if you activate the Guildmage’s second ability, that infinite life combo also becomes a win condition, draining your opponents down to zero. (Note that Guildmage’s ability says “each opponent” so this win condition works in multi-player, as well.)
It’s fairly easy to see who wins here. You might play Orzhov Guildmage in a Commander deck, even one with this combo in it, but Vizkopa Guildmage is the enabler. This is an easy win for the new kid on the block.
WINNER: Vizkopa Guildmage, for enabling infinite combos that lead to win conditions.