Repeating my comments from the "Cards we want to see" thread, I think what we need is a card that turns Dori's ability from being useful in rare corner cases to being more generally useful. (I see no chance of positive errata, unfortunately. Has there ever been errata in this game to make a weak card stronger?)
What I want is something that helps out Dori a lot, but doesn't have to be used with Dori. And that means synergy with his rarely-useful ability.
So his ability
1) Exhausts after defender is declared
2) Adds his defense to another hero's defense for one attack.
The edge case where this ability is useful is where you don't need Dori's attack or defense for anything, but you need to buff a hero defender to take some massive attack (or another player's hero when Dori's player has no enemies). I see two angles:
1) Get rid of the exhaust cost somehow. Without the exhaust, Dori can buff a defending hero and still attack (making him solo-friendly), or potential buff multiple hero defenders in a multiplayer context.
2) Give some extra benefit for adding defense.
For #1, something like this would really help Dori
Tactics 1 attachment -- Unexpected Valor. When a Hero exhausts not to quest, defend, or attack, exhaust unexpected valor to ready him.
This makes Dori useful even in solo, and the attachment is in-sphere. It's also extremely useful for other heroes with an exhaust ability (Beravor, Denethor, Elanor, Haldir, Galadriel, Merry), but most of the other heroes have once per round limitations and only Dori has the attachment in-sphere. The attachment would also be handy for attachments that exhaust themselves and the hero, but again that's not repeatable and only in-sphere for Great Yew Bow.
For #2, something like this would be useful
Tactics event (cost 1?) -- Counter-stroke. After a hero defends without taking damage, do damage to enemy equal to the hero's attack.
With that, Dori's loss of action advantage can be worth it, because by buffing the defense of a good *attacking* hero he can potentially enable substantial direct damage. Suddenly Dori becomes useful in a Gimli deck, serving as a defender most of the time but enabling the occasional massive counter stroke. But it's also a card that doesn't require Dori to be in play to be handy in a deck. (Maybe it should be "after a character defends", though?)
I think you’re right. I don’t remember any player card ever receiving positive errata. And I would love to see something come out to make his ability more useful.
As for your suggestions, I would love to see something like that ready effect but I would prefer it to be neutral at a higher cost. 1 is a little OP but in tactics I can’t think of anyone else it helps but this guy.

