I was thinking about a new psionic power (well, from XCOM 2012) as well as a change in Psionic Line of Sight Rule for Mind Probes only.
New Psionic Power: Mindfray: Mindfray is an offensive Psionic power that can be used by Sectiod Leaders and Commanders, Ethereals, and XCOM Soldiers with Psi-Amp. Mindfray generally is easier to use than Mind Control, harder than Psi Panic. When Mindfray is used, the target must make a Psionic Strength Test against the user's Psionic Strength and Skill. Successful save will result in no effect. Failure will result in the target taking health damage, ignoring armor and the target's psionic strength will decrease for one turn. The target's accuracy and morale will decrease the same was as with other health damage, but Mindfray will not deal any fatal wounds. The lower the target's psionic strength, the more damage to health and Psionic strength is taken. Mindfray can kill if blasted enough times, and can potentially kill soldiers with pathetic Psionic Strength in one hit.
Mind Probe: The LOS rule has made the mind probe much harder to use, but I believe that there should be a change to that. The standard scan will use 50% time units and require Line of Sight, but the new action, Relay Scan, uses 100% Time Units but does not respect line of sight.