It has many different possibilities though from this. Theopaschism can be Orthodox as well as heretical, as viewed in a Monophysite point of view. This was one of the major objections to Peter the Fuller's addition and innovation to the Trisaigion Hymn. To many it seemed (and continues to seem) to have Nestorian, Sabellian, and Monophysite connotations and views that must be held.
From the context of your post, and other posts you have made over the last 24 hours, I take it you mean the Oriental Orthodox when you used the word Monophysite here. It's a violation of forum policy, but I'll let it slide.
For explanations of how the OO version of the Trisagion is neither an innovation or heretical, please click on the "trisagion" tag below. In particular, see EA's explanations here:
http://www.orthodoxchristianity.net/forum/index.php/topic,7178.0.html