If you want to equip all of your favorite MultiVersus characters with the coolest cosmetics, then you'll need to purchase Gleamium.
All 3 Ways to Get GLEAMIUM in MultiVersus (A Must-See!)
Unlike other MultiVersus currencies like Gems, Gleamium is much scarcer and only available in limited quantities unless you open your wallet. Since the available skins in the Player First Games release increase with each content update, you may need more Gleamium to collect all the cosmetics in the catalog.
The fastest and cheapest way to get Gleamium in MultiVersus is by redeeming gift codes. This list of MultiVersus codes is constantly updated with new promo offers that reward players with bonus Gleamium for free.
The disadvantage of this method is that the codes are not always available, so you have to check the list regularly for new offers.