Adjust Asura Strike
The original design of Asura Strike was as a powerful blow to finish off an opponent that is only to be used as a last resort. This is accentuated by the fact that the skill leaves the monk with the inability to naturally regenerate SP after use. However, as time went on, people came to abuse the skill more and more to kill MVPs in combination with Lex Aeterna and a variety of SP regenerative items. This leaves some room for adjustment to be considered to bring the act of hunting MVPs back into the originally intended goal of a party rather than a single player.
Adjustment number 1: Remove capability to regain SP completely and persist through logout upon use
This fix I think is more in line of the original design, since it was obviously intended for the monk to not be able to quickly reuse the skill in succession, however the natural regen disability wasn't punishing enough to those who would abuse the skill. I think this adjustment would somewhat help the reliance on the skill alone to kill MVPs, though it comes with the downside of players that are determined to solo may just raise multiple monks on their account to cycle between to bypass the added restriction. This brings me to the second option
Adjustment number 2: Apply a damage cap to the skill
Setting a high damage cap on the skill would still allow those determined to rely on it to use it, but not to the extent where it's the one and only option players go to for killing MVPs. It would take longer to put MVPs down with the skill alone and perhaps drive players to think of another approach to MVPing, hopefully going back to playing in a party as the overall intent.
Overall, the intention is to bring MVPing back to a party objective. I understand there may be side effects of the first suggested adjustment for WoE, so if the skill could have the effects differ in PvM vs PvP, then that might not be an issue. However if that framework is not available, then setting a high damage cap on the skill may be preferred since it would only impact the MVP hunting aspect of the game as intended, while still having a potential value higher than any player could reach if it's still intended to be usde as a 1 hit kill for WoE purposes.
This is just an idea to help the diversity of how the MvP scene is addressed in game. If other areas of the game had a 1 size fits all solution, it would also warrant additional attention and fine tuning.