Basic Attributes consists of Stats that will affect your Valkyrie's Overall Performance on the Battlefield. So far there are 5 main stats that can be enhanced with proper Gear and Affixes.
The 5 Main Attributes is as follows:
HP - is short for "Hitpoints" (or Health Points for some), the HP stat will dictate on how much damage your Valkyrie can absorb before going down. If their HP reaches zero, that's where they die, so always be mindful of their HP and switch her out if needed.
ATK - is short for "Attack", this stat represents the Valkyrie's base attack and the stat that will be multiplied by damage multipliers. This stat will influence on how much damage the Valkyrie can deal through all of her forms of attacks.
CRT - is short for "Critical", this stat affects the Valkyrie's Crit Rate, the Crit Rate stat will dictate how often your Valkyrie will be doing Critical Hits through her attacks. Critical Hits are basically attacks that deals higher damage than usual. So far (As of Ver. 5.3) only PHYSICAL damage dealers can benefit from this stat.
SP - is short for "Skill Points", this stat will affect the maximum amount of SP that the Valkyrie can hold at a time. SP's are usually used to activate Weapon Skills and Valkyries Ultimate Skills.
DEF - is short for "Defense", this stat will affect how much damage is reduced when receiving damage from incoming attacks.
The Main Things that can influence these 5 stats are Weapons and Stigmata. Weapons usually affects ATK and CRT (Upper-Right corner).
While Stigmatas with the right affixes can affect several stats. Depending on the Affixes, the Stigmata will have different stats to modify.
Applying affixes is very simple, you just need to tap or click "Refine".
Then it will take you to this menu.
So far, each Stigmata can only have a maximum of 2 slots of affixes. Usually, a newly obtained Stigmata only has 1 affix slot or none at all, however if you upgrade it to its maximum level, there's a chance it will generate 2 affix slots. But just in case it doesn't, you just need Normal Crystal Cores to unlock the 1st slot and Normal Crystal Cores and a Crystal Flashtank to unlock the 2nd slot (Price varies depending on the rarity).
The Crystal Flashtank's main source is through Weekly Finalizations on Open World.
Be warned though, if you're new, you don't have to think about Affixes for the meantime as Affixes are completely random when rerolling...which basically means it potentially requires A LOT of Normal Crystal Cores to get the desired stats.
Additional Info:
SP or Skill Points can be replenished through doing basic attacks. Skills that consumes SP's are usually Weapon Skills and the Valkyrie's Ultimate skill (Ult for short). You can see how much SP you have by looking at the yellow bar below the Valkyrie's HP bar.
Usually when killing enemies, they drop SP packs, SP packs replenishes 15 SP for your Valkyrie. SP packs looks like orange glowing cubes (Or it looks like an orange "Atom").
Some Valkyries doesn't require SP in order to activate their Ult skills, such as Stygian Nymph, although if there is SP prior to activating her Ult, all of her SP is consumed to boost her attack.
