Weird question

[blackmage_nuke]

If by "no consequences" that also means there's no afterlife or whether i go to heaven/hell is not effected and this is known to me as a fact, then yes I'd off one of the more unstoppable brutally inhumane dictators. That is if a means to perform the murder is also provided as I assume I don't have the knowhow to choreograph an assassination by myself.
If it has to be someone i know personally and actually have a means and opportunity to kill then probably not unless I personally knew an unstoppable brutally inhumane dictator.

If the possibility of an afterlife is still unknown to me and "no consequences" only applies to real world consequences then I wouldn't kill anyone. Souls and/or lives may or may not be sacred and its not up to me to make that decision.

edit: Though if I KNEW there was NO afterlife, I might go nuts and just kill any human who is a hindrance in the pursuit of immortality (eg politicians and bureaucrats who would oppose stemcell research or something) assuming I can perform as many non-consequential murders as I like, ultimately becoming the unstoppable brutally inhumane dictator I once hated so much