Actually in LoL you have 4 abilities (1-2 of them may be passives) AND an INNATE ability, which is like a fifth, always passive ability that you cant upgrade. This one is usually referred to as simply champion's passive.
In dota there is no innate, you have 4-6 abilities that you upgrade, and you can also upgrade your base stats.
To put it simply, it should be dota character not being sure what a passive is rather than lol character.
Maybe the joke is on the fact that Riven does not have any passive ability (except for the innate).
It's more that dodging or missing autoattacks is no longer a mechanic in LoL ('cept for Jax).
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That blurry effect you see is just her passive... Umm, how should I explain that...She is watching you...She wants to be your friend!Her face is pale, and is very blurry!Hi... hi...When Riven Meets Rylai (3)No! She's actually a really kind girl!Look, this is her photo!Gulp... Ohkay...She... is in front of you... But you can't see her on the minimap...Wait wait! Are we talking about ghost stories? It sounds really creepy...