I just posted the imgur pictures . It says imgur on this post to find my pictures of my aftermath gear affixes and the original affixes the aftermath gear comes with. Affixes are stats on the items like 4395 weapon dmg + or %, Hp 5000, mp on hit 143, 1 extra attack chance, 15% poison dmg, etc. Those are affixes. There are many different types of affixes; they are: Normal affix (yellow affix), Epic affix (orange affix), legend affix ( red affix), crystal affix (bright blue affix) and set affix ( green affix). To add these affixes, you use the larimar crystal for normal affixes, topaz for epic affix, ruby crystal to add legend affix, amethyst to add a set affix and obsidian to add crystal affixes. Also you could use angelite crystal to add epic or normal affix but it has a chance to remove your precious affixes which could downgrade your item from rare to magic and its not worth it. There is the mythic affix but you need 4 mythstone slots and specific mythstones to obtain them which is very hard and thats how mythic items are created.
My gear has crystal affixes due to using 3 obsidian crystals from the kind developers who gifted it to me and everyone else. Also if you do happen to get nadroji ring or amulet, this gear will be even more powerful . Also definitley get fortune to 20+ for better chances of legends/crystal/eternal legends. There are no eternal affixes as of yet at the moment though and unfortunatley you cannot add or remove affixes from eternal items or any other applications except use calcite to change element of eternal items.
Also set affixes add up to the number of items you wear. In my case, since i have 4 equipment with aftermath affix, it would add up to 4 and this is aftermaths full power. At 1, its 25% chance for meteor reset, shatter, fear proc etc, at 2 , its 50%, at 3 ite 75% and at 4 its 100%. They go up in 25% for each equipment piece.
Aftermath is a very powerful affix because in full power, as long as you get mp easily, you can shatter then press meteor summoning meteors constantly without cooldown stopping you. Its even better with 40 hero points because you can summon over 5-10 meteors or more in seconds then reset cooldown to do the same cycle again. With cosmic power, it speeds up the process, adds more meteors because of mirror images and you can teleport really fast as well.
I hope this explains this well to you and hope you suck less at this game.