An ancillary power pool or patron power pool (both also known as epic power pools) are power sets that become available for most archetypes at level 35. Arachnos Soldiers and Arachnos Widows have access only to patron power pools. Peacebringers and Warshades do not have access to any ancillary or patron power pools. Just like the regular power pools, you can choose a different APP or PPP during a respec.