Unimitated

But Falstaff, unimitated, unimitable Falstaff, how shall I describe thee! thou compound of sense and vice; of sense which may be admired, but not esteemed; of vice which may be despised, but hardly detested.

Source: wiktionary

The eloquence was plainly "in the man, in the subject, and in the occasion," but most emphatically was it in the MAN. Webster's extreme solicitude to make his style thoroughly Websterian--a style unimitated because it is in itself inimitable--is observable in the care he took in revising all his speeches and addresses which were published under his own authority.

Source: wiktionary