Mauls current set up all he needs is health. That's it. Buff his health up to around 5s and he becomes a issue that needs to be taken out fast, but if they have Rey, qgj, Gs now you really have to decide what to do. Kill maul before his power in unleashed and let Rey, gs and qgj destroy you, or take them out ( like always ) and take mauls fury. Maul becomes a very good toon with just added health ( very high health ).
But my opinion is he needs a complete over hall. He should be fast, evasive, with some lock down skills, as he has faced multiple enemies at once many times.
Skill examples. Just like dooku on hit to Jedi, chance to stun and/or ability block. Chance to reflect blaster fire. Chance to attack a 2nd time at a random target Chance increases as he takes dmg. Turn meter reduction chance. Lower def/off with his AoE.
Not saying all of these, saying 1 of them or something like it. Yes his dmg would have to be toned down some, if he is even powerful now. No one really knows due to his slow speed and low health as no mater he strong he might actually be he is a complete waste of resources to find out.