Both diana and akali are assasins, of course you'll rack up kills with both, and with a big gold advantage victory often comes as well.
Then one day comes a team clever enough to get this thing called MR/CC and focus you down. I like diana as well and got a somewhat of a positive win/loss ratio with her, but both are very vulnerable to cc and reliant on the enemy team either being pants on head retarded or only have damage from one hypercarry. Your job is pretty much to either pick somebody off or jump through the frontline and kill a high priority target, where as the former is most commonly only applicable when playing against knobheads. You got no innate escape but your flash (or ulti to a minion if you're lucky enough to have one nearby), play more than two games and you'll start noticing how she drops of severely against loads of bruisers or getting shut down.
Then one day comes a team clever enough to get this thing called MR/CC and focus you down. I like diana as well and got a somewhat of a positive win/loss ratio with her, but both are very vulnerable to cc and reliant on the enemy team either being pants on head retarded or only have damage from one hypercarry. Your job is pretty much to either pick somebody off or jump through the frontline and kill a high priority target, where as the former is most commonly only applicable when playing against knobheads. You got no innate escape but your flash (or ulti to a minion if you're lucky enough to have one nearby), play more than two games and you'll start noticing how she drops of severely against loads of bruisers or getting shut down.