So my personal suggestion is, use your brother's account just for discussion.
I won't recommend you give him that advise. OP, "prevention is better than cure". The moment you start using the account any previous reputation of that account becomes invalid. It's far better to abstained from destroying what your brother (may his soul rest in peace) have investing timeless amount of time and dedication to built out of your own greediness.
Sure you might promise yourself not to abuse any system with the account but life can happen at any moment. Your emotions might cloud your judgement and you go meriting yourselves or trusting yourself just to have advantage over other for some privileges like signature slots etc. Create your own account and build your own reputation.