Sona Passive=DAFUQ?! SHE'S SUPPORT??? WHAT?!!!!

So recently I had a game where my adc went afk(I cant find the match for some reason, it's probably a bug but I'll try to bring it up when riot fixes the bug). I was a Sona support with Support masteries and ap runes. I find it confusing that I won lane against a malphite support and jinx adc, for I scored first blood and a double kill at the same time without having to use any potions or let the turret do damage to them. You simply bait them down and then E W Flash Q Auto to get double kill. You repeat E W Q auto and I took 1/8 of the malphite's HP along with his passive somehow, which I found bullshit considering how some top laners can't even do that and a sona with support masteries can. And I would take 1/4 of Jinx's HP with the E W Q auto combo. Like hell! Later on, when I had 4 items done (Frozen Queens, Athena's Unholy Grail, Lich Bane, Sorceror's Boots), I would just E W Q auto and do 5/8 of a aurelion sol jg's HP, and he wasn't underfed or anything.