So i've been watching the stream a bit and i think i figured out the meaning of those symbols (the crossed swords, blue flame, orange flame)

Crossed swords = X killed Y

Orange flame = X has a killstreak, killed Y

Blue flame = X iced Y's killstreak

Am i Right?

actually i think corssed swords = auto attack
blue flame magic damage skill
red flame physical damage spell

but i really didnt look too close at it, you might be right, that's just what i expected

anyways for spells they should just display the icon of the ability that got the killing blow..

oh just read a red post on NA forum about this, turns out i was right

i think it's a nice touch.

when you're on a streak you're hot (orange flame), then somebody cools you off by killing you hence dousing you (blue flame).

although blue flames are actually hotter than red, but i'm guessing nobody cares about physics at riot (which may explain their crappy programming).

still like the ability icon idea more.