Not all Hydreigons are violent, if it helps. Mine's always been kind of a coward, but I'd say it varies. Helps if you don't use too much aggression.

[But hmm, temporary workarounds. He pauses for a moment, tapping his chin.]

Ever thought about having one of your Pokémon guide it around? Could always give it treats whenever it's not acting up or cover the floor with pillows, I guess.