Talon doesn't simply walk around invisible and instantly kill you with no warning either. He has to press R giving you a huge visual and audio warning that he's coming and ample time to group up, which is vastly stronger and more consistent in ARAM's forced 5 man lane play, AND THEN he has to reappear and hit Q->W->AA->2nd hit W + possibly another AA to kill a SQUISHY target. DON'T FORGET that W has a huge delay on the return and a TON of his damage is loaded into his DoT passive meaning his kill power is delayed and can be counterbought by Zhonya's and counterplayed by shielding, healing, CC, mobility spells and outright being focused and ofcourse killed by all 5 enemies before he can pull his combo off.
Now add Oracles to the "counterbought" list and you just have a balanced assassin that is now an unfairly gimped one. All the above applies to Kha Zix's and Akali's in-fight weaving playstyles as well, which are entirely cemented in the pseudo-defense of invisibility to where they cannot function if they are simply visible 24/7.
ANOTHER THING is that if someone who has Oracle's Zhonya's as Talon ults, Talon will not only be unable to attack them but that unit will still also reveal Talon from within the Zhonya effect for their team, effectively acting as an old SR pink ward and invalidating Talon even further.
pole and 
pool gimp 25 abilities simultaneously at the push of a single ability.