Glyph of Paralysis and Glyph of Repulsion combo. My main recommendation that all Arcane Warrior builds should use Glyphs:
What talents and spells should I be getting? The bonuses from constitution and willpower can be easily replaced with equipment, for magic that is much harder.You will deal more damage both with spells and later on with your physical weapon.You will increase your spellpower, meaning that enemies will not be able to resist your spells, even if they are bosses.It may be difficult at the start of the game if you are playing on Nightmare, but later on, the payoff is huge:
I suggest investing ability points all into Magic. It will unlock some additional quests for a lot of gold during the game.
Moreover, Arcane Warriors from a lore perspective were elves This gives you a large boost to Magic that will be your main attribute. When creating your character here is what I suggest: You have a few important decisions to make in the early game that help you maximize how well your build will go through the Dragon Age world.
