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I advise you to first capture two or three Dark faction castles, so you have somewhere to retreat to when you see Erin on the map (the strongest Dark hero on this map, always travels with a large and formidable army), while simultaneously building the first Elven town that you are given at the beginning of the game... And, of course, the more castles you have, the more money you'll earn.
Then, gather an army (preferably from all available Elven towns; if you don't care about morale, you can combine it with Dark faction troops if you have a large number of them)... Although, on this map, the army is only needed to defeat neutral creatures and fend off individual Dark heroes who will sometimes aggressively pursue you and try to take your towns... You should always have at least one town in reserve!
And then (or at the same time as all of this), quickly run around the map and look for the Tear.
The goal is to first eliminate all the Dark Elves on the map, and only then start searching; it's better not to do it the other way around, as you will waste a lot of time and effort; it's better to quickly run from one marker to another... The main thing, I repeat, is not to encounter Erin