Cassandra sees no use in speculating on what enemies they may or may not face. As for strategy, hers can generally be described more or less as "charge in with blade swinging," so she doesn't offer any input on that, either.

To Thranduil's question, she replies, "Stone and steel alone could not have held Corypheus. We know that the Wardens used magic to bind him. It is likely that the spells were bound up in objects themselves, artifacts left here to keep him trapped when the Wardens sealed the prison. If those artifacts still exist, they may provide some clue as to how to stop him."

She falls silent as they step further onto the bridge, alert for any sound, either of darkspawn or other creatures below, or of the bridge itself beginning to fail under their weight. But the stone holds, and soon enough they're (relatively) safely across the bridge.

The doorway into the prison has been torn from its hinges, leaving a dark, gaping maw behind. Hesitantly, she reaches a hand out - but there's no shimmer of magic blocking their way, and after a moment, she steps forward into the darkness, hand on the hilt of her sword.