Warrior's quest

import java.util.Scanner;

public class firstProblem {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        String skill = scanner.nextLine();

        String input = scanner.nextLine();
        while (!"For Azeroth".equals(input)) {
            String[] commands = input.split("\\s+");

            switch (commands[0]) {
                case "GladiatorStance":
                    skill = skill.toUpperCase();
                    System.out.println(skill);
                    break;
                case "DefensiveStance":
                    skill = skill.toLowerCase();
                    System.out.println(skill);
                    break;
                case "Dispel":
                    int index = Integer.parseInt(commands[1]);
                    String charToChangeWith = commands[2];

                    if (index >= 0 && index < skill.length()) {
                        String charToChange = skill.substring(index, index + 1);
                        skill = skill.replace(charToChange, charToChangeWith);
                        System.out.println("Success!");
                    } else {
                        System.out.println("Dispel too weak.");
                    }
                    break;
                case "Target":
                    String substring = commands[2];
                    if ("Change".equals(commands[1])) {
                        String substringToReplaceWith = commands[3];
                        while (skill.contains(substring)) {
                            skill = skill.replace(substring, substringToReplaceWith);
                        }
                        System.out.println(skill);
                    } else if ("Remove".equals(commands[1])) {
                        while (skill.contains(substring)) {
                            skill = skill.replace(substring, "");
                        }
                        System.out.println(skill);
                    } else {
                        System.out.println("Command doesn't exist!");
                    }
                    break;
                default:
                    System.out.println("Command doesn't exist!");
            }
            input = scanner.nextLine();
        }
    }
}