The doctrine of the unseen realm as a mastery ladder — the reality and nature of angels, their ranks and ministry and the angel of the LORD, the fall of the angels, Satan's names and tactics, Christ's victory over the powers, the nature and activity of demons, spiritual warfare and the whole armor, and the sober Reformed posture for the believer today. Each mode trains a different skill; the final exam ranges over the whole course. Unlock each subtopic by scoring at least 90% on its mastery check. Cards you grade enter spaced review: the dashboard tells you when they fall due.