I've heard of Telegram betting bots, but your Discord casino might indeed be one of a kind. However, originality is not automatically a good thing. By making your casino on Discord you're limiting the number of potential users to those using Discord and willing to use Discord for this purpose specifically (an analogy with Telegram is that while I have it for personal use, I wouldn't want to have gambling there because of some private info being exposed this way, and because different platforms have different purposes). I wish you luck but succeeding in this competitive environment is hard.