NetherRealms.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace random
{
    class Program
    {
        static void Main(string[] args)
        {
            // SortedList <string DEMON NAME, Dictionary<int HEALTH, double DAMAGE> >
            SortedList<string, Dictionary<string, double?>> demonBook = 
                new SortedList<string, Dictionary<string, double?>>();
            string dragonPattern = @",\s*"; // used in dragon extraction
            Regex extractNumbers = new Regex(@"(\-?\+?\d+\.\d+|\-?\+?\d+|\d+)"); // used in number extraction
            Regex extractMultAndDiv = new Regex(@"[*\/]"); // used in symbol extraction
            string[] input = Regex.Split(Console.ReadLine(), dragonPattern);

            foreach (string dragon in input)
            {
                int health = dragon.Where(Char.IsLetter) // extracts the letters from input
                    .Select(c => c - '0' + '0') // converts each letter to its numeric value
                    .Sum(); // sums the values
                
                // extracts all numbers (with + or - sign and double or int)
                MatchCollection damageMatches = extractNumbers.Matches(dragon); 
                double damage = 0d;
                foreach (Match match in damageMatches)
                {
                    damage += double.Parse(match.Value); 
                }
                
                // extracts all * and / symbols
                MatchCollection symbolMatches = extractMultAndDiv.Matches(dragon);
                foreach (Match match in symbolMatches)
                {
                    if (match.Value == "*")
                        damage *= 2;
                    else
                        damage /= 2;
                }
                
                demonBook.Add(dragon, new Dictionary<string, double?>());
                demonBook[dragon].Add("health", health);
                demonBook[dragon].Add("damage", damage);
            }

            //
            // Output
            //

            foreach (var dragonValuePair in demonBook)
            {
                Console.Write(dragonValuePair.Key + " - ");
                foreach (var typeValuePair in dragonValuePair.Value) // iterates the nested dictionary
                {
                    if (typeValuePair.Key == "damage")
                        Console.Write($"{typeValuePair.Value:F2} {typeValuePair.Key}");
                    else
                        Console.Write($"{typeValuePair.Value} {typeValuePair.Key}, ");

                }
                Console.WriteLine();
            }
        }
    }
}