Velocity: Mechanics

Split Second: As long as this spell is on the stack, players can’t cast spells or activate abilities that aren’t mana abilities. Used on 6 cards: Sudden Death, Instant Growth, Take Possession, Sudden Shock, Ragesung Oracle, Startlemander

Momentum: At the beginning of your end step, if this creature attacked, put a +1/+1 counter on it. Otherwise, remove all +1/+1 counters from it. Used on 4 cards: Rampaging Brute, Savage Venomblade, Rageflame Acolyte, Disciple of the Ebb

Primary G

Dash: You may cast this spell for its dash cost. If you do, it gains haste, and it’s returned from the battlefield to its owner’s hand at the beginning of the next end step. Used on 8 cards: Sprinting Scout, Barreling Huntbeast, Lunging Warrior, Aetherwaft Shaman, Xerka, the Lance, Alexa, Voice of the Wind, Vicious Runner, Bloodlust Berserker

Primary R

(A creature battles when it deals combat damage or fights.): Used on 0 cards:

Agility: This can’t be blocked, except by creatures with greater power than toughness. Used on 5 cards: Stuntbuster Patrol, Burning Rageblade, Intellectual Duelist, Rummaging Corsair, Swashbuckling Bravo

Primary W

Velocity: This creature can’t be blocked, except by creatures tapped to block it before your declare attackers step. Used on 0 cards:

Official rules:

Tap an untapped creature you control: Designate the tapped creature as a blocker of this creature. Only any opponent can activate this ability, and only on your turn before your declare attackers step.

This creature can’t be blocked, except by creatures designated as a blocker of this creature. Tapped creatures may block in this manner.

Evasion:

: Prevent the next X damage a source would deal to this creature this turn. You may activate an Evasion ability no more than once each turn. Used on 0 cards:

Finesse: A creature with Finesse gets +1/+0 for each noncreature spell its controller has cast this turn. Used on 0 cards:

Momentum: At your end step, put a +1/+1 counter on this if it attacked and has less than PARAM1ASWORDS +1/+1 counters on it. If it didn’t attack, remove all +1/+1 counters from it. Used on 1 cards: Lifeblood Floodmaster

Throttle: You may have this creature enter the battlefield with a haste counter. If you do, it can’t block. Used on 0 cards:

In card text or details pages, write the mechanic's code name (playtest name) between square brackets, like "[Crittercast]", "[Bushido 1]" or "[Delay 4 {2}{R}{R}]". It will be expanded to the mechanic's name plus reminder text, such as "Suspend 4 – {2} {r} {r} . (Rather than cast this spell from your hand,...)"
To expand a mechanic's name but not its reminder text, include parentheses at the end of the square brackets: "[Crittercast()]", "[Delay 9 {R}()]".