Regarding the loyalty effect: -50 loyalty is really not that OP imo. We have the same effect for Mapuche's 'Swift Hawk' (with -20 loyalty for each kill in the cities's borders), but this can possiby trigger way more often (The unit causing the effect usually doesn't die - or at least not as an inevitable consequence of the action itself).
Even multiple -50 loyalty hits are non-issue in core cities with no loyalty pressure, so don't worry about getting turned the capital.
For fringe cities with decreasing loyalty, it can be devasting, though. But here, it is the very idea of the ability. As it is a one-time effect for each rock band (unless the city has multiple "gig sites"), and the band can dissolve after the concert as well, it has to be on the stronger side.
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One other thing (I wrote this in the live-stream thread already):
Maybe, purchasing a rock bands should require a 'broadcast center' in the city.
This would fit thematically and limit "band spam" as well.
Reliquious units can only be purchased in cities with 'holy sites' after all and archeologists require a cultural district with museum.
Even multiple -50 loyalty hits are non-issue in core cities with no loyalty pressure, so don't worry about getting turned the capital.
For fringe cities with decreasing loyalty, it can be devasting, though. But here, it is the very idea of the ability. As it is a one-time effect for each rock band (unless the city has multiple "gig sites"), and the band can dissolve after the concert as well, it has to be on the stronger side.
--
One other thing (I wrote this in the live-stream thread already):
Maybe, purchasing a rock bands should require a 'broadcast center' in the city.
This would fit thematically and limit "band spam" as well.
Reliquious units can only be purchased in cities with 'holy sites' after all and archeologists require a cultural district with museum.