My friends and I actually did this sometime around the second game and basically ended up with Nisha, Wilhelm, and The Doppelganger, but I had a Siren idea that they haven't done! I don't remember all the specifics, we actually wrote out everything because nerds, but I probably tossed it so here's what I can remember: The Action Skill created an AoE pulse of electricity around her for a bit and increased her melee damage and speed. One of the trees was all about electricity. Increased damage, AoE radius, chain lightning, and I think the final skill was like a huge shockwave. Another tree was all support. Buffing the teams shield capacity and recharge speed while in the radius, increased movement speed, reload speed, and the final skill allowed you to activate your ability while down and bring yourself and everyone in the radius back up. I really liked the last one, it was all about debuffing! Enemies would be stunned by every pulse, move slower, attack slower, and deal less damage to friendlys. The final skill turned any enemies in the field into temporary allies! It was definitely overpowered