Disclaimer - I'm not personally familiar with this game.
These characters (based on info at the Wikipedia entry) don't exist in Tolkien's writings - they're inventions of the game.
Tolkien's writings however do cover events of a northern (relative to the main action in Gondor and Mordor) extension of the War of the Ring, with several other battles occurring "off-camera". These are best summarized in Return of the King Appendix B: the Tale of Years; I'll list the major such conflicts here and refer you to that source for further info:
- First Battle of the Fords of Isen
- Second Battle of the Fords of Isen
- Invasion of Eastern Rohan
- First Assault on Lórien
- Battle of Mirkwood
- Second Assault on Lórien
- Battle of Dale and Siege of Erebor
- Third Assault on Lórien
- Destruction of Dol Guldur
Of the locations at the same Wikipedia article, Nordinbad and Urgost Lair are non-Tolkien (inventions of the game), but everything else is in Tolkien, although some of it may be scattered across multiple different sources (some not in wide circulation). Note however that under the terms of the Middle-earth Enterprises License, only material from the Hobbit and Lord of the Rings may be legally used, and so any information about a location that comes from other sources should not be present here.
Since so much important information is collected in Unfinished Tales, the History of Middle-earth, and essays published in periodicals (such as the Rivers and Beacon-hills of Gondor essay - a key source) it's therefore impossible for any licensed work to depict many locations how they really are in Middle-earth - licensed works are just not legally allowed to use that information.