Console app that runs sts2.dll outside Godot to benchmark damage-per-turn of arbitrary decks. Uses Harmony shims to bypass Godot native interop and TestMode/NonInteractiveMode to short-circuit SceneTree-bound waits. Phase 1 (state machine): draw, exhaust, multi-hit, self-damage, energy, block — all verified against expected card behaviors. Phase 2 (modifier pipeline): power application + ModifyDamage hooks + end-of-turn tick-down — Vulnerable amplifies Strike from 6 to 9 and expires after 2 turns as in real combat. Throughput: ~6,300 turns/sec in Release. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>