{Ye also helping together on our behalf} (sunupourgount(936e)
kai hum(936e) huper h(886d)(936e)). Genitive absolute with present active
participle of late compound verb (sun and hupourge(935c) for
hupo and ergon). Paul relied on God and felt the need of the
prayer of God's people. {By means of many} (ek poll(936e)
pros(9370)(936e)). Pros(9370)on means face (pros, ops). The word is
common in all Greek. The papyri use it for face, appearance,
person. It occurs twelve times in II Corinthians. It certainly
means face in eight of them ( 3:7,13,18  8:24  10:1,7  11:20 ).
In  5:12  it means outward appearance. It may mean face or person
here,  2:10  4:6 . It is more pictorial to take it here as face
"that out of many upturned faces" thanks may be given
(hina--eucharist(8874)h(8869) first aorist passive subjunctive) for the
gift to us by means of many (dia pollon). It is indeed a
difficult sentence to understand.