The DevExpress Support show me a way to solve my problem:
Image img = new Bitmap(300, 300);
Graphics g = Graphics.FromImage(img);
Font schriftart = new Font(StyleVerwaltung.Instance.Schriftart,
StyleVerwaltung.Instance.SchriftgroesseDruckInfo);
StringFormat format = new StringFormat();
format.Alignment = StringAlignment.Center;
_Report.Watermark.ImageAlign = ContentAlignment.BottomLeft;
_Report.Watermark.ImageViewMode = ImageViewMode.Clip;
g.SmoothingMode = SmoothingMode.AntiAlias;
g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
g.TranslateTransform(0, g.VisibleClipBounds.Size.Height);
g.RotateTransform(270f);
g.DrawString(text, schriftart, Brushes.Black,
new Rectangle(0, 0, (int)g.VisibleClipBounds.Size.Width,
(int)g.VisibleClipBounds.Height),
format);
g.ResetTransform();
g.Flush();
_Report.Watermark.Image = img;
_Report.Watermark.ShowBehind = true;
It uses the Watermark to accomplish this task. It just works if you dont use Watermark in other context but for my goal it works as expected.