The first two letters "AJ" is meaningless.
then this stentence means that :sth is the most unorthodox had been ever invented,this unthordox thing was invented through some mathmetic simulation,AJ is trying to understand this most unorthordos thing,
这句话的意思是AJ 正在集中精神去试图理解这个通过数学上的模仿而建立的神秘物体.
这句话里who 引导一个句子做主语的同位语,像one who...这样,sth后面的that引到一个句子做sth的表语,对sth的具体内容进行解释说明,而unorthodox是做that的表语,这里省略了谓语动词is,即that （is） unorthodox ever...后面through所引导的成分做invented的伴随状语,用作说明invented的具体方式.
本来应该解释为他试图通过模仿来理解这个有史以来最异端的东西,但是后面的their与前面的his mind不搭配,所以只好解释成上面一种.