The definition of Komar Mass in GR is associated with one asymptotically flat end. However, a hypersurface may contain more than one end, such as the spacelike Einstein-Rosen bridge in Kruskal Spacetime which has two ends.
Therefore, the total mass is conserved by the Stokes theorem and current conservation, but how is Komar mass associated with each end conserved?
In the example of Kruskal Spacetime with parameter $M$ in the Schwarzschild metric, the total mass integral is certainly zero for the vaccume solution, with the Komar mass associated with two ends are $M$, $ -M$ respectively. So we know that $ M+(-M)=0$ is conserved, but why $M$ or $-M$ is conserved?