Stone Mechanics
Infinity Stones, though not entirely unique to the VS. series, adds a new dimension to the game by allowing you to select a stone during character select and change the outcome of battle. Stones offer the ability to change your experience in how the game is played, even if you use the same team! Finding the stone that fits for your team is important but experimenting with multiple stones is encouraged.
There are two primary functions for a stone, the Surge and the Storm.
Surge
The Surge is a basic one button input that acts as a special attack, stones can be chained or canceled from any normal or command normal and can cancel into hypers. Each time a Stone is used, it builds a bit of Stone Guage Meter which when built to 50% or above, can activate it's Storm. Learning how to use each stone's Surge is extremely important in neutral, combos and mix-ups.
Storm
The Storm is an important come back mechanic that grants you special abilities based on your stone. Storm can be activated multiple times per match once you reach 50% of your meter which is built by either taking damage or through the continuous use of your Surge, even if it doesn't hit your opponent. You also gain a large chunk of Stone meter when your partner is killed as long as you aren't already in your own Storm. You can activate Storm during combos or even during block stun and gain a large portion of invincibility, though you aren't at frame advantage. By activating Storm again while it's active, you get a free level 3 at the cost of your remaining Stone Gauge. Strong use of your Storm will be optimizing your buffs and using the last bit of your Storm meter to get access to a level 3.
Tip: As soon as you activate your Storms Level 3, your Storm immediately ends frame 1 and if your opponent has enough gauge to activate Storm, they can do so to escape your level 3 by gaining invincibility.
All Storm activations are 27 frames long and fully invincible through it's duration.
Stone Selection
Reality
The Reality Stone's Surge is a low priority, slow moving homing projectile that can be reflected. Seen as a strong stone for it's simple use of being able to track your opponents movements, it can help supplement a characters zoning tactics or offer additional support for characters who have none. Only one Reality Stone can be on the field per character, you can always Surge then tag and Surge again to have two on the field at once. This projectile goes away on hit or block and can be reflected back, if the projectile goes away you gain access to use another immediately. It's important to know that if Reality is on the field and the user who activated the stone is attacked, Reality will remain on the field and can help break combos.
Reality Storm is a powerful tool that adds elemental attacks based on the button you press, like the Surge, you can get two elemental attacks on screen if you tag. 
is a small wind attack that can be rapid fired, however this attack does no hit or block stun. 
is a fire beam that spawns based on the height your character is currently at when activated. After a short delay, a full screen beam of fire will attack horizontally which is excellent for lock down but has minimal hitstun. 
is an ice attack that can only hit grounded opponents and will temporarily freeze them if hit which is great if you anticipate your opponents tag. 
is a thunder bolt that attacks from the sky vertically which is good for keeping your opponent out of the air, has minimal hitstun.
Surge: 9f Start up, 2f Active*, 40f Recovery.
- Reality is active until it runs out of duration or until it hits opponent, travels about 3/4 full screen
Pick Reality if you want extra zoning support or a projectile you can use anywhere on the screen and tag out under the cover of this projectile. It's slow speed forces opponents to respect it, however it doesn't have too much durability and can be destroyed by most projectiles. This can be a double edged sword as opponents can also reflect this projectile back and will then track the original user. The Storm is strong as each of your normals can become powerful elemental attacks and through the use of Active Switch you can have up to two elemental attacks on the field at once.