Camille healing with the Death's dance item makes no sense

Since when is her 2nd Q aoe? With a single i heal for 41 hp on my second Q at lvl 12, i buy and i start healing for 28?? How does that work again? And how come my W heals me for 122 without and 104 with?? Isn't the 33% heal from death dance and addition to the base heal of the W? Is this item broken only on her or on most champions? No wonder almost no one uses the item.