Henamarth Riversong is probably the best (non-gandalf) ally in the core set. One for one and one is pretty good, but that ability crowns all! It pretty much shuts down the encounter deck in a single player game. If you're running a lore hero.... and not Henamarth.... you're doing it wrong.
Action: Exhaust Henamarth Riversong to look at the top card of the encounter deck.
The Fellowship of the Ring
Core Set #60. Lore.
Here he is, the holy grail of solo game. First of all the price. For cost of one you get nice 1 and 1 and he can be very quickly added to any non-lore deck using with Stand and Fight and any discarding mechanism as got Éowyn for example or simpy use Song of Wisdom because for cost 2 he is still worth it. His ability is really great, because if you use him at the end of the round you will actually know, what the next encounter card in quest phase will be and you can really prepare for it during planning phase. If you pair him with Denethor he is even better. You can use Denethor at the end of round to check the next encounter card and if its terrible, discard it and then use Henamarth Riversong to check what the next card will be. If you got Unexpected Courage and Ever Vigilant in hand, you can discard this way two encounter cards even before the quest phase starts. This is the closest solution to control encounter deck I knew about. Very important card for avoiding nasty treacheries and really strong enemies. A game changer. Artwork is also very nice. Verdict: 5/5.