There are many good poison type/ steel type you can get at that point of game which can be used against Adrienn. I played the game a few times and i find that nidoqueen is really good in that battle. I personally recommend you to try on your own since its definitely beatable and the challenge is good to improve your own skill but if you really want a high level poison type pokemon like venusaut, i can get you one. I got all poison type in the game, so just message me if you still need one.