TxtTransposition

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

namespace TxtTranspose {
    static class Program {
        static void Main(string[] args) {
            var txt = @"
XCUALOVEYKBWSNG
DUAWKCBEAUTYRJV
YOUTHFSMGNEZLPR
MHJREYWDKZLUSTJ
FSUCCESSDHEALTH
ENMQXPTIMELMSAQ
VEXPERIENCEGHBW
GHUMOURLOYMONEY
SYZPOPULARITYNA
AMKCFUNBXHUZYIX
CWIHYSHAPPINESS
HONESTYCFRIENDS
KPYJAETWPOWEROC
BTYACFREEDOMJMO
RIWINTELLIGENCE".Trim().Replace("\r", "\n").Split(new char[] { '\n' }, StringSplitOptions.RemoveEmptyEntries).ToList();

            var results = new List<IEnumerable<string>>();
            results.AddRange(txt.RotAll());
            results.AddRange(txt.Mirror().RotAll());

            foreach (var result in results) {
                Console.WriteLine("======");
                foreach (var line in result)
                    Console.WriteLine(line);
            }

            Console.ReadLine();
        }


        public static IEnumerable<string> Mirror(this IEnumerable<string> foo) {
            foreach (var bar in foo)
                yield return bar.Aggregate("", (p, q) => q.ToString() + p);
        }

        public static IEnumerable<IEnumerable<string>> RotAll(this IEnumerable<string> foo) {
            IEnumerable<string> bar = foo;
            for (int i = 0; i < 4; i++)
                yield return bar = bar.Rot90();
        }

        public static IEnumerable<string> Rot90(this IEnumerable<string> foo) {
            for (int i = foo.First().Length - 1; i >= 0; i--)
                yield return foo.Aggregate("", (p, q) => p + q[i]);
        }
    }
}