Essential Skills for this Trial:
This trial requires both Tanks to use a Purge on boss 1 and 4, on boss 1 you may need to use Balance to sustain using it as you need to cast purge a lot.
For boss 1 the Off Tank will also need Crushing Shock to ranged interrupt all of the spheres around the centre of the room. On second boss the Main Tank needs it to interrupt the Main Boss if it teleports out of group and begins channelling.
Pulsar can be really helpful on add pulls, 4th boss and for the Minor Protection in last boss execute.
Shield Charge or some other gap closer is useful on boss 4 but not essential. But it is essential for Main Tank on last boss after you get punched by the main boss, you have to gap close quickly.
General skill setup can be found here: