Titanic Hydra active is incredibly buggy with high AS champions.
Hydra is meant to be an AA reset but it behaves oddly. There is such a huge delay between the active and the AA after it that it is most definitely slower than a normal auto attack. At very high AS it seems like it would be faster to just AA rather than use the active as an AA reset.
Super easy to recreate. I can feel the effect on Volibear with nothing but his frenzy buff and AS runes. He just stands there like an idiot for a full second after using the active, even with 1.50+ AS.
Edit: Since someone is already confused, let me be precise. Upon using the active, your next AA is incredibly late. You effectively lose AS moments after using the active. It's gamebreaking when you use the active and just stand still while your target gets away or kills you.