deputy, subordinate, procurator, low-level, placeholding, precursorial, antirequisite, preventive, prelusive, preventative, more...

real, actual, genuine

voting proxy, shares proxy, proxy server, proxy war, more...

good, reasonable, poor, rough, transparent, useful, reverse, crude, appropriate, local, general

for someone else,   a stand in,   third-party account,   on someone's behalf,   narrative stand-in,   substituting as,   on one's behalf