Aggro cass usually plays to dominate the very early game and get the opponent to 15-7 health by the time they start loosing on the board. Cards like Demonic Lure, Bloodtear Alchemist, and Soelljammer help a lot.
When you start to loose steam with the board, you switch to either an offensive face rush strategy, with Tigers, Flameblood, or Spectral Blade or a slower chip strategy with Desolater, and Voidpulse. Whether to play more chippy or more aggressive depends on how confident you are that the opponent can’t kill you quickly, or how much heal they are running.
In the past, Revenant was used as a finisher. Now, Alpha, Revenant, or Unleash can be used as finishers, if you feel like you need one. Reflection can also pull surprise lethal.