an outstanding person among mediocrity ❍ 卿所谓～，庸中佼佼者也。(《后汉书·刘盆子传》) You should be regarded as an outstanding person among mediocrity and a giant among dwarfs.
铁中铮铮tie zhong zheng zheng
person of true caliber
铁中铮铮tiě zhōnɡ zhēnɡ zhēnɡ
铮铮：金属撞击所发出的响亮声音。比喻出类拔萃的人物或事物。distinguished among men, an outstanding person among mediocre people