Program.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace Tsukasa
{
    abstract class PushDownStateMachine<StateType>
    {
        protected Stack<StateType> StateStack;

        public PushDownStateMachine()
        {
            StateStack = new Stack<StateType>();
        }

        public void PushState(StateType command)
        {
            StateStack.Push(command);
        }

        public void PushStateList(IEnumerable<StateType> commandList)
        {
            foreach (var command in commandList.Reverse())
            {
                StateStack.Push(command);
            }
        }

        public void EvalState()
        {
            while (true)
            {
                if (StateStack.Count == 0) return;

                if (DispatchState(StateStack.Pop())) return;
            }
        }

        protected abstract bool DispatchState(StateType state);
    }

    enum TacticalMethod { Attack, Guard, DubleAttackAndGurad, Wait };

    class Knight : PushDownStateMachine<TacticalMethod>
    {
        protected override bool DispatchState(TacticalMethod command)
        {
            return command switch
            {
                TacticalMethod.Attack => Attack(),
                TacticalMethod.Guard => Guard(),
                TacticalMethod.DubleAttackAndGurad => DubleAttackAndGurad(),
                TacticalMethod.Wait => Wait(),
                _ => false,
            };
        }

        private bool Attack()
        {
            Console.WriteLine("Attack!");
            return false;
        }
        private bool Guard()
        {
            Console.WriteLine("Guard!");
            return false;
        }
        private bool DubleAttackAndGurad()
        {
            PushStateList(new List<TacticalMethod>()
                            {
                                TacticalMethod.Attack,
                                TacticalMethod.Attack,
                                TacticalMethod.Guard
                            }
            );
            return false;
        }
        private bool Wait()
        {
            Console.WriteLine("Wait(Halt)");
            return true;
        }
    }

    class Program
    {
        static void Main()
        {
            var knight = new Knight();

            knight.PushStateList(new List<TacticalMethod>()
            {
                TacticalMethod.Attack,
                TacticalMethod.Guard,
                TacticalMethod.Wait,
                TacticalMethod.DubleAttackAndGurad,
            });

            knight.EvalState();
            Console.WriteLine("====");
            knight.EvalState();
            Console.WriteLine("end");
        }
    }
}