ideally after as much downhill as possible
lol, you have to go up to go down!
I walked the Offa’s Dyke Path bit in the photo above over Christmas, one way from Llandegla to Llangollen. It is beautiful but Esclusham, Eglwyseg Mnts have been very wet and boggy, much more so than usual winters. The bridleway part of Offa’s Dyke through Llandegla Forest and up to road is boardwalked in places, but it is very slippy. Where there is no boardwalk, the path is just a stream. The paths in that area are mostly rolling around the contours of the hills, where they run straight downhill they are usually forestry / logging tracks.
The MapMyRide is all on road. The area described as World’s End is around km 30, OS ref SJ232475 ish. The whole of the panorama route past Castell Dinas Bran and Vale Crusis Abbey is lovely but not very MTB. Note, the crags have an access agreement for climbers outside of the bird breeding season and the Offa’s Dyke Path goes through a number of SSSI, so I would encourage you to stick on the bridleways and roads and enjoy the scenery or look for MTB routes on the south side of Llangollen or from Cyrn-y-Brain around the Horseshoe Pass.