Skull and Shards, absolutely. When an Exotic like Celestial Nighthawk provides not only a damage bonus, but also 33% super energy on a kill; other exotics that only provide super energy need to be more powerful. Skull simply needs a straight up buff while Shards needs an overhaul on how the buff works. Shards is stupid OP in Mayhem, but that's because the Exotic gives increased regen rather than a straight chunk of super energy. Orpheus Rigs and Ursa are fine as is to be honest. Ursa can easily get you 75% of your super back if you are using it effectively. I could actually see a slight nerf to Ursa. Orpheus only gets you back 50% when used effectively, however, this is plenty given not only the potency of the super when it comes to add clear, but also the ability to get a decent amount of super energy back from killing tethered adds. Phoenix does not need a buff, but a slight nerf would be fine as well (get it, Well...)