Board Thread:Question and Answer/@comment-29547733-20161006025454/@comment-29474392-20161006033340

I believe that yes, she's most most like to appear at the end of a witchgate as reward. I'm not sure whether you're more likely to receive her if you've fought her in the witchgate.

I have cleared quite a lot of witchgates this event too, hoping to have her drop. So far I've received 1 Elsa and 3 Leviathan but no Leona. It's all a matter of luck. I've had events when the UR has fallen easily from Witchgate, and others when she hasn't dropped at all.

Best of  luck to you.