Whenever Niv-Mizzet, Guildpact deals combat damage to a player, it deals X damage to any target, target plater draws X cards, and you gain X life, where X is the number of different color pairs among permanents you control that are exactly two colors.
![Niv-Mizzet, Guildpact (Serialized) [Murders at Karlov Manor]](http://www.cardmerchanttakapuna.co.nz/cdn/shop/files/537835.jpg?v=1765376621&width=1445)