InterceptCommand during the guard step. The interceptor leaves its circle, becomes the power reference for the attack and goes to the drop zone at the end of the battle; the original target survives. Grade 1 cannot intercept, back row only with InterceptFromBackRow granted by an effect. Five tests.
Cards of grade 0 and 1 have boost by default (HasBoost); CardInstance.BoostOverride lets an effect grant or remove it at runtime. AttackCommand takes an optional BoosterSlot: the back-row unit in the same column adds its power for that battle only and becomes rested. Four new tests.
Solution on .NET 10 LTS with rules, content and CLI projects. Content importer pulls stats from the official card list, merges trigger/rarity data, emits three YAML sets (94 cards, 124 printings). Validator checks the grade-0 shield invariant, sentinel shield, parallel printing links, and deck construction limits. 14 tests cover catalog integrity and deck validation.
MpakobecEx