In DKS the Demon Wars book 'only' gives 3 skill points, rather than the 5 it did in the original release of Ego Draconis.
However, you should be able to read the book whichever trainer you picked, immediately after looting it (or later). If you can send it to the battle tower chest, try doing that and go take it out again.
There are better sets (one for mage, warrior and archer - see the guide below) and unique equipment in the Flames of Vengeance section of the game. However, there are also lots of malachite gems to be had then, as well, if you reload at veins and when turning in certain quests (some give 2 or 5 randome gems in the optional quest rewards, which can be malachite).
At the end of DKS I had 65 malachite gems, using a couple for healing auras and giving up 2 for a quest.
Dragon Knight Saga FAQ/GuideI didn't use any summons, but I believe the favoured ones are the ghost (for its extra healing particularly in the early game, but it remains effective if you keep it levelled) and demon (from what I've read the best fighter summon).
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