What is not disputed is that some of his works are adaptations of Roman Catholic works, in particular (1) Spiritual Exercises of Ignatius Loyola, the founder of the Jesuits, using an Italian edition with commentary by Giovanni Pietro Pinamonti (1632-1703); and (2) Unseen Warfare, which was a translation of Spiritual Combat by the Catholic priest Lorenzo Scupoli, He was not the first Athonite monk to translate a Catholic work as an Orthodox one: in 1641, Agapios Landros (17th c.) published The Salvation of Sinners, but it was simply a translation of Dialogus Miraculorum, written in the early 13th c. by a German Cistercian, Cæsarius of Heisterbach Abbey. Such works were influential at least in part due to the assumption that they were products of the Athonite monks who published them, rather than works by Roman Catholics.

There is continued disagreement about the provenance of Nicodemus' Exomologetarion, his manual for confession... Metropolitan Kallistos Ware holds that the Exomolgetarion is "mostly a direct translation" of two books on confession by the Italian Jesuit, Paolo Segneri (1624-1694) Bishop Basil of Wichita in his introduction to the “Exomologetarion” (linked under sources below) argues for the edifying value of St. Nicodemus’ work from an Orthodox perspective.

The twentieth-century scholar Christos Yannaras is perhaps the severest critic of St Nicodemus' influence, seeing the negative effects of the West not only in his adaptation of Catholic books, but alleging the saint’s use of Roman canon law in The Rudder (Πηδάλιον,Pedalion), adoption of the Anselmian view of the Atonement, and acceptance of the Catholic practice of indulgences. (There is an extant letter by St. Nicodemus to Bishop Paisios of Stagai that Yannaras construes as requesting an indulgence, and promising financial payment for it.) Yannaras also sees the influence of Western pietistic moralism in Nicodemus; Chrestoethia of Christians (1803), in which he condemns musical instruments, dancing, (non-liturgical) singing, the telling of jokes, etc., and tells Christians that such conduct will lead not only to their own punishment, but to the death of their unborn children. Yannaras points to both the Exomologetarion and Nicodemus' other compilation of canons, The Rudder, as imposing a Western, juridical approach to the Mystery of Repentance (Confession), saying that "This pastoral approach, however, provoked opposition, contempt or indifference in the laity: one traumatic confession in the new judicial format might make people cut their ties with the Church." At least one Athonite elder, St. Porphyrios (Bairaktaris) the Kapsokalivite, also found using the Exomologetarion harsh and counter-productive and ceased to use it for that reason.

https://orthodoxwiki.org/Nicodemus_of_the_Holy_Mountain

“The Greeks [Orthodox] . . . are not heretics or schismatics but the most Christian people and the best followers of the Gospel on earth.”

- Martin Luther

Source: Luther, Martin (1999). Vol. 32: Luther’s Works

'Photius promised everything, and was accordingly consecrated, but by the very same Gregory, and took possession of the See. Six months had not yet passed over, since his consecration, and he had broken all his oaths and promises; he persecuted St. Ignatius, and all the ecclesiastics who adhered to him; he even got some of them flogged, and by promises and threats induced several to sign documents, intended for the ruin of his sainted predecessors. Not being able to accomplish his design, he laid a plot, with the assistance of Bardas, that the Emperor should send persons to take information, to prove that St. Ignatius was privately conspiring against the state.'

St. Alphonsus Maria de Liguori

St. Nicholas Church in NYC