Each time you open a Mad Love loot matrix, you'll receive a new rare or epic item and the chance to unlock a bonus legendary item increases each time you open one! (atlasreactorgame.com)
Being able to purchase legendary items from various vendors is costly as well so prepare to put in a lot of playtime to get the best of the best gear. (cogconnected.com)
The best method is to just keep earning Legendary items. (cheatcc.com)