1. Quests; people who give quests like Bang often give yen and charka shards, they usally give you powers and swords as well.
2. boss battles; when you fight a boss you can get a lot of charka shards but not much yen. It is best to get charka shards from this way but if you want yen do somthing else. Each dimension has a diffrent boss apart from the tournamet dimension.
3. Just do what ever; you can get yen and charka shards every minute but it only give five charka shards but the higher rank you are the more yen you can get!
4. boxes; There are boxes around the map that give you charka shards(usally 80) but it does not give you yen.
5. tournamets; Go to the tournamet dimesion and fight others to eran yen and charka shards. You can even get tournamet tokens which can buy stands, sword skins and more.
6. buy it when robux; yeah we all know we can buy it with robux. just press the button with the shoping cart and your there.
7. fighting pass; you don't need the fighting pass for yen(not charka shards) because you still can get yen every five levels! But you will not get anything else unless you have the fighting pass which costs 40k charka shards.