Sylas BUG on URF

That's not a bug.

If there's a Kalista on the enemy team, Sylas starts with that item and can mark someone as his Oathsworn. They just leave it in the shop regardless of whether or not a Kalista is actually in the game. If she's not there, it does nothing.

That's...not a bug. That's an intended mechanic in all modes.

Otherwise he literally couldn't use a Kalista ult.

How else do you think he will be able to use Kalistas ult? #NotABug