As a unit, Nami joints a lot of unusual mechanics into her Tidal Wave. Outside of having the best Crowd-Control in the game, Her ability also buffs allies Auto-Attacks, giving her a remarkable good synergy with auto-attacking classes such as Ranger, Blademaster and Berserker, granting hybrid damage to them.
However, there is more as Nami also shares all item's buffs to her allies once she hits them with her Tidal Wave:
If Nami is turned into Inferno, her allies Autos will cause burn damage.
Morellonomicon causes her allies autos to burn units for % HP and reduce their healing.
Rabadon's Deathcap causes allies spells to have a 75% damage amp abilities, as long as it hits them before they cast.
Active - Tidal Wave: Summons a massive tidal wave which deals 150 / 250 / 350 magic damage to all enemies hit, knocking up and stunning them for 1.5 / 2 / 2.5 seconds. Allies hit are empowered for the next 8 seconds, making their basic attacks deal an additional 25 / 50 / 300 bonus magic damage on-hit.