So my school is going back to full face to face and I am curious if I am bound to certain things under pain of sin of omission. Something I felt more worried about is preaching to someone who is Greek Orthodox since unlike prots, orthos receive the Eucharist to their own condemnation. I also have an aunt who is Greek Orthodox and my Godparent and sponsor from the novus ordo is dating a Greek Orthodox woman and is attending their schismatic services. I don't know how to go about telling my Godparent/his gf about this stuff nor my aunt or the kid from school. Does anyone know of any quick things that could be put in a pamphlet against the schismatic Orthodox?

I would suggest taking down some notes from this video to include in your pamphlet: