What is another word for "alter"?

Roget's Thesaurus (1911) lists these synonyms for "alter": abettor, ablegate, accessory, accomplice, accredit, acquaintance, acting, adherent, adjunct, adjutant, adjuvant, advocate, after, all, ally, alone, ambo, amigo, among, and, angel, answer, appear, archon, assistant, associate, auxiliary, backer, bedfellow, behalf, best, boon, bosom, brief, candle, casual, centesimal, certain, chamber, champion.