10 supply
12 rax
13 refinery
15 Reaper
17 OC
* 17 supply
@50 gas, pull out SCVs
18 factory
** 19 refinery
21 supply
23 port
@100% port, tech lab immediately
* After this depot is done, I normally send this SCV to the proxy location, and unless the map is huge like Whirlwind, it should get there in time. If it's a map like Bel'Shir Vestige, you may want to send a different SCV earlier around the long way so it doesn't get scouted.
** When this is done, take one SCV from the other gas so you have a 2/2 split on gasses.
EXECUTION: I like to put my first two marines at the most obvious Reaper spot, but that might mean you don't cover the ramp - personal preference. Around the time the second rine pops is when a 12/12 Reaper will hit your base, it's important you micro against it and keep your rines together. If they are doing mass Reaper, once you start getting picked off, there is this snowball effect where you can just straight up die to it, but I guarantee you this build should not die to it (non-proxied) if you are hitting your production correctly because the 1st Hellion will pop in time.
If they are going mass Reaper, you can sit at home with your ground army and let the proxy Banshee do the work OR you can split your army, leaving a few units at home + production reinforcements to defend Reapers (you can always pull some SCVs) OR you can send your entire army towards his base if you've killed some Reapers and/or you're confident he went home with them. If there hasn't been more than one Reaper, I move out at 3-4 rines and rally the factory that will maintain constant Hellion production to them.
I suggest always poking into the natural because if he's expo'd you might get some free rines, if there isn't anything at the natural you can risk poking up the ramp to see what he has and possibly attack or wait for the first Banshee. Just make sure your Banshee is rallied near his mineral line. The idea of the ground army is primarly to thin out his Marine forces and only secondarily to draw his attention, you don't need to attack at the same time as the Banshee hits; I generally attack a bit before the Banshee finishes because for Terrans doing Hellbat drops, this is usually their weak time depending on how greedy they've been. Say they have two Hellions out and some rines (which will clearly win), just pull back and concave at their ramp for now waiting for reinforcements, instead of losing your ground army. When the Banshee hits the worker line, work on any advancing Marines before the workers because killing army is good too.
IMPORTANT: If you scout Hellbats, continue the Banshee attacks, don't ever ever send them home. If they manage to get a turret up, scoot around it and pick things off. It's only ever acceptable when they get a Viking out or you can do no more damage. Make a bunker near your mineral line and send back whatever remaining ground forces you have left. Makes marines and a tank. The Hellbats will come before you have time for an Ebay and turret. The bunker buys you time to get a turret up and a standing army that won't melt to Hellbats. Turtle up until you can safely take your natural and play on.
IN GENERAL: This isn't meant to kill the other guy, but it can - it is a technical rush. In any case, I always throw down an eventual expansion, then get a tech lab on the rax (then Stim ASAP) and factory since I like to transition into bio tank when I feel they've held off the ground attack. I also make one Medivac before sending my port back home; however it'll take forever to get back and might get sniped, so I usually start another at home after my core production facilities are done. The build came about as my personal hard counter to mass Reapers when every Terran was doing it. Turned out to be good against Hellbats too and all-around pretty decent.
Replay: http://www.gamereplays.org/starcraft2/replays.php?game=33&show=details&id=283586
