Felsteel Demon Hunter - Darkmoon Races

In general, you would want to keep your card-generation cards like 'Illidari Studies' and 'Wandmaker' to get spells that could help you in your matchup. Drawing cards is also a key part of DH so cards like 'Chaos Strike' are good too.

Against aggro matchups, its important that you have early game removals. Illidari studies can be use to generate an 'Eye Beam' or a 'Consume Magic' to help you survive the early game. Having cheap minions like the 'Manafeeder' or 'Wandmaker' in the early game could also help to cool down early aggressive plays. Having your 'Warblades' ready in the early game could also help due to its lifesteal.