Like my ST breakdown, a friend asked me about Mas. He quickly became one of my favorite champs to play as, so I decided to share what I've learned with him. Just click the spoiler:
Masacre
Swing away, Mas... swing away...
Bonus points if you know the movie reference... anyway... Masacre.
1) Be aggressive - unlike other champs, Mas benefits from an aggressive playstyle.
2) Always hit into a block - never give up the chance to hit into a block. It is highly beneficial for Masacre. If possible, use a 4 hit combo when the opponent is blocking.
3) Why hit into a block? - Mas' bat attacks have great block penetration. They do great damage with minimal power gain. Also, each blocked bat attack grants an ignition charge.
4) Ignition charges - You gain a charge from a critical hit or a blocked bat attack. Every time you crit, it does an additional amount of burst energy damage. For every charge, you do an extra 10% burst damage with a crit (up to 100%). Your goal is to get to 10 charges as quickly as possible to ignite your bat.
5) Ignited - This is his end game. Once you are ignited, every bat hit will incinerate the opponent. Once the opponent is incinerated, Mas' damage really ramps up. Incinerates destroy defense against bat hits. Additionally, Mas gains power like hitting the opponent if they block a bat hit. So, always aim for that 4 hit combo block attack once you debuff them. Your crits also do 100% additional burst damage.
6) Heavy - not really useful as you can gain ignition charges much easier and more quickly with blocked hits.
7) sp1 - like his heavy, I hardly ever use it. Some people do it to refresh debuffs, but I find it cuts into his DPS. The only time I use it is against direct counters (more on that in a sec).
8) sp2 - The creme de la creme of his attacks. Never combo into this attack. You want the opponent to block it. It does way more damage blocked than if it hits. For each ignition charge, it does more damage... and if the opponent is ignited... woah damn. They basically explode when they block it. Another thing about this attack is it's nearly 100% safe to shoot off anytime. If it hits, it hits. If it's blocked, any incoming attack will miss for .75s. This allows you to immediately start swinging again to increase pressure. There are exceptions, though...
9) Direct counters - anyone with defensive AAR such as PM or OG Ultron will totally mess up Masacre's gameplan. These champs prevent ignition charges from blocked hits, block damage of sp2 and the .75s delay on a blocked sp2. If possible, avoid these match ups. If not, use sp1.
10) sp3 - pretty worthless; avoid if possible
11) Dupe - it's not necessary, but it does significantly up his damage and increase the rate at which you become ignited
That's Masacre in a nutshell. He's so much fun to play. Let me know if you have any questions.