Babylon 5 Wars game material is sanctioned as cannon by JMS.... supposedly

It makes good reading material though I don't think JMS really thought all that background before creating B5. OK, maybe an inkling like a general story about the First Ones and the Shadow War but not complete histories on every First One that appeared in "Into The Fire".

Ships are hard to describe but basically...

Walkers of Sigma 957 you've seen in "Voices of Authority".

The Triad is the ship that appears like a 3 pronged crown which fires like a vorlon ship.

The ThoughtForce is the last race contacted by Lorien and Ivanova in the beginning of "Into the Fire".

Torvalus Spectators I don't know how to describe. Dask, help me out here.

Krishiac Lordships is the little ship that has multiple engine thingies floating near the primary body, which looks like an asteroid.

That's the other Ancients I think.

With regards with who can vie with Lorien, I think the question is moot because no being in the galaxy [even our volatile race called Humans] would ever touch him.