Superman (vol 3) #687 VF

POWER AND WEAKNESS

While Superman leaves the planet Earth to take care of business on New Krypton, he leaves Mon-El in charge of protecting Metropolis. Mon-El has taken-up the secret identity of "Jonathan Kent" and has joined the Science Police. Guardian and the Science Police battle against Shrapnel. Mon-El feigns unconsciousness as Jonathan Kent, and appears as Mon-El – ready to battle Shrapnel one-on-one! After taking care of Shrapnel, Mon-El asks Guardian how he did. Guardian expresses concern about Mon-El's secret identity and it being revealed if he continues switching back and forth between Jonathan Kent, Science Police, and Mon-El, Super-Hero, during battles.  Meanwhile, several villains are contemplating heists in Metropolis since Superman is gone. Fortunately, Black Lightning and John Henry Irons seem to be planning counter-measures to this anticipated surge of crime. Jimmy Olsen visits Zatara to ask him questions about suspected magic in a recent fight that Superman, Supergirl, and Krypto had against Atlas.  Guardian calls together Science Police Officers Foster, Jamie Billi Harper, Romundi, Sanderson, Wilcox, and Jonathan Kent for a dangerous, volunteer-only mission to rescue an old friend. But the next day, after capturing Plastique, Mon-El abruptly learns that his powers are gone!