From early game to late game progression, rings are going to be essential in every classes playthrough. You will gain far more bonuses from these than any other particular gear pieces and should always become a priority when you are hitting a new class change.

Skills are what drives our characters, whether you are playing on auto all the time or manual. Do you want to play a pure class or would you like to have the best of both worlds? Here you will be able to get the necessary skills to push your class further.

These mounts, though limited, have very important purposes. The Starhorse mount will provide you a stacking exp buff while fighting monsters across the MU region while the Bloaning Devil will provide you a lot of support in PvP engagements by being able to remove a buff off the player you are attacking. This can really turn the tides of your gameplay and I would recommend getting both throughout your playthrough

Though you can pick these materials up through various other parts of the game sometimes these drops from monsters and bosses just are coming to you as fast as you may need. The Garnet shop has you covered as long as you have the garnets to purchase them. These will be crucial in upgrading and evolving your gear and even crafting your pets and other armor sets later in the game. 

If you are planning on trying out the "Hybrid" way of life within MU Dark Epoch or want to pick up a few skills. You will need to understand how to get the stats you need without replacing your gear pieces and that's where these come into play and allow you to reset your selected stat by a certain amount so you can reallocate them elsewhere to pick up the skills you need

Pets are helpful little companions that bring with them some nice stat bonuses that will change upon evolution and set tier. Each serving it's own purpose in providing support to it's master, you!

Runes are going to be an investment in any playthrough and require a large amount of garnets to collect them all to fill the slots in your gear. Take your time with these as there is no rush to socket all purple runes. You will gain access to blue and green through your normal dailies but these are the only ones that can be upgraded. 

If you are starting out, make this a habit to pick up weekly. As you learn and grow and play through this vast world of MU, you will collect so many items that your bag and storage will be bursting at the seems. These expansions will help to make it easier for you to accommodate all the things you will acquire throughout your journey and allow you to start stockpiling some of the things you will need more of