Materia are items in Crisis Core: FF7 Reunion that allow players to use many abilities. Such abilities include using command powers, boosting stats, casting spells, summoning monsters, and offering capabilities during combat. These boosts can be distributed among the five Materia types: Command Materia, Independent Materia, Magic Materia, Summon Materia, and Materia.
These Materia types can actually be combined to make a brand new Materia; this mechanic is called Materia Fusion. This mechanic offers players the ability to create up to 143 different types of Materia, but it is important to keep in mind that this item only gets a limited number of slots in Crisis Core: FF7 Reunion. It is recommended to use Fusion Materia during gameplay because this type of Materia is generally more powerful than that of uncombined Materia.
Mug
According to The Gamer, Mug is one of the best Materia to get quickly in Crisis Core: FF7 Reunion. Mug is an Independent Materia that increases the chances of Magic Pot appearing, interacting with this enemy can potentially level up Zack faster than that of other enemies. Mug is created from Steal Materia and Electrocute Materia and can be purchased from Junon Souvenirs.
Dualcast
Dualcast is a Materia that allows Zack to cast two spells while only channeling it once. This action is completed at the cost of doubling the Mana Points in Crisis Core: FF7 Reunion. This Materia is obtained by purchasing it from the Network Shade Shop, stealing it from Makonoid, or in a chest found in Mission: 9-4-1: Genesis's Ambition.
Full Cure
Full Cure is a Magic Materia in Crisis Core: FF7 Reunion that offers players a higher recovery rate than that of Curaga. In fact, it restores all HP to one or more party . This Materia is obtained by stealing it from Magic Pot or Goliath.
Status Ward + Hell Blizzaga
The use of both of these Materia simultaneously allows Zack to become immune to any status ailments that they may inflict. This is extremely useful because this power also gives players the ability to inflict many status ailments upon enemies. It is important to note that the SP, or Soldier Points, need to be at high levels in order to boost this Materia's abilities through Crisis Core: FF7 Reunions' Digital Mind Wave (DMW) feature.
Status Ward is a Materia that can be created by fusing Stop and HP Up. Hell Blizzaga is a Magic Materia that is made up of Dark Blizzard and Octaslash. Status Ward can either be purchased from the Wutai Secret Shop or obtained through a chest found in Mission 9-5-2: Further Below. Hell Blizzaga Materia can be purchased from the Wutai Secret Shop or found in chests while completing Mission 2-3-1: Unidentified Monsters, Mission 4-4-2: Death Wish for Zack, or Mission 6-4-2: In the Closed Coal Mines.
Costly Punch
Costly Punch is a Command Materia that is fused from Goblin Punch and Octaslash in Crisis Core: FF7 Reunion. This Materia produces the most amount of damage in the shortest amount of time. Additionally, Costly Punch ignores the target's VIT, which is the vitality of the player, but it comes at a cost. The HP of the player will decrease when this action occurs. The Materia for Costly Punch is typically obtained in Mission 9-5-4: Abnormal Power or stolen from Mako Ifrit.
While this game offers many base Materia types, it is recommended to use the Materia Fusion mechanic to create stronger version of Zack. In fact, using multiple Materia Fusions simultaneously in combat is by far more effective than using one Materia Fusion by itself. Because there are many types of enemies in Crisis Core: FF7 Reunion, players are encouraged to experiment with these combinations to find the best Materia types for their style of gameplay.
Source: YouTube/BattleScar1313, The Gamer