When Lyonesse sank, the shadowpath was seriously damaged. Through significant work, a group headed by Liam, Malachi and Dominic managed to repair and re-open the shadowpath for use.
Lyonesse has an alliance with Amber stretching back millenia. Currently, however, there is not much in Lyonesse to ally with. Trade routes are kept open with Lyonesse as a matter of respect. But without a centralized government, Lyonesse has little formal connection to Amber in its current state.
Before the Deluge, High King Mark accepted non-aggression treaties with Pathi, and allowed them to seek out potential mages within the borders of Lyonesse - assuming the local nobles were also in agreement. As the Deluge swept across Lyonesse, some of the few mages dotting its lands sought refuge in Pathi, in exchange for swearing an oath of loyalty to the mageocracy.