Before I make my suggestion, let me say that I really like the changes made to Beregond with 4.3.1. They really make Beregond stand out as a Hero, as well as really define his role in the faction.
Now I wanted to make a post about this ability around the time 4.3.1 came out, but I have had the worst luck when it comes to getting Gondor when I choose Random, which is pretty much always.
Beregond's level 8 ability (the one with the German name), in my opinion, is incredibly overpowered once Beregond is level 10. 30 seconds of Invulerability to both Heroes and Buildings in a very large radius is way too much. Let me put this into perspective. Thorin Oakenshield needs to be level 10 to have his Invulerability to affect all nearby heroes. Thorin costs 2600 and is the faction leader of Ered Luin. Beregond costs 1000, and his ability also effects all nearby buildings, which makes Gondor's defensive capabilities better then they already were.
And this is just 1 ability. Beregond also has a lot of others that, while not overpowered, are very good abilities. But with Beregond the way he is now, it is a flat out mistake not buying him in a match. He improves offensive and defensive capabilities of the entire faction to the point where they can come out of pretty much any situation victorious.
Of course, that is the way I see it. Maybe it isn't as drastic as I make it sound. But right now, I would say that Beregond's level 8 ability needs very heavy nerfs.