Tiberium Twilight

It also gave the world its first taste of the Tiberium Universe, where the UN-backed Global Defense Initiative is locked in a brutal war with a quasi-religious militant group, known as the Brotherhood of Nod, and its infamous leader Kane.

In a refreshing twist to the ultra-real war settings of other RTS games of the time, C&C also introduced a hint of sci-fi with the arrival of the strange alien substance tiberium. This strange crystalline material mutates everything in its path and is the main catalyst behind Nod and GDI's worldwide campaign.