Incidentally, dear reader, if you would like a say in what I highlight for a forthcoming build post, I have another thread for you to voice your opinion. As before, I'll take informed and uninformed opinions, because
General Notes & One Giant Caveat
The Executioner shares a trait with the Nova: Lots of fixed equipment, including lots of heat sinks. Depending on how aggressively you shave armor, the Executioner will wind up with between twenty-five and twenty-seven tons of pod space available and a minimum of sixteen heat sinks, after you've stripped out everything you can. This means that, like the Nova, the Executioner will tend to favor energy weapons for their lower weight and for the fact that by filling your remaining crit slots with more heat sinks, you wind up with one of the highest heat dissipation rates achievable at present.
Beyond heat sinks, though, a lot of your tonnage is taken up by mobility equipment: eight tons of jump jets and four tons for MASC. When you pilot this mech, make sure you take full advantage of this equipment, or that's tonnage gone to waste. Use your jump jets to take shortcuts that other assaults can't utilize or jump snipe with the PPC and Gauss builds. Use your MASC to boost your acceleration and deceleration, when you're peeking out from behind cover, and don't forget to use it to sprint to help you clear long jumps or more generally keep up with your team's heavy and medium mechs. Your top speed is a plodding 69.7kph without MASC, but you can sprint at 90.5kph. A ninety-five ton slab of mech traveling at over 90kph is a scary sight.
Unlike the Nova, the Executioner does not have any significant quirks. If there is a section of the mech that does not house any weaponry, you're free to use whatever omnipod you like for that location. On the torsos, that doesn't mean much, but on most of my builds, you'll see me use the D left arm, despite none of the highlighted builds utilizing any missiles. This is because that omnipod allows for the use of a lower arm actuator, partially unlocking horizontal movement for both arms, allowing more effective use of the many lasers that I will frequently have mounted on the right arm.
Now, to that giant caveat.... As I write this, patch day was two days ago, and that patch came with the most significant balance changes that we've seen in a while. Of particular importance was an increase in UAC jam times, particularly for the UAC10 and UAC20, which saw a sixty-percent increase in jam time and a slight increase in jam chance. The Clan UAC5 saw less extreme changes in the same direction--an increase in jam chance and an increase in jam time. Most of my time playing the Executioner took place before this patch, and my time since the patch has been in a build without UACs. Consequently, this post is going to discuss my pre-patch experience, which will not be reflective of the current state of the game, in the case of UAC-equipped builds. (There are some non-UAC builds included in this post, which should perform as described.)
Finally, the Executioner is an omnimech with no center-torso hardpoints or quirks, so I will be splitting the builds up by effective range, instead of by variant. For reference, I purchased the Prime, A, and D variants, since that minimized the amount of (shockingly expensive) omnipods that I had to buy for my initial builds. Even to make my final builds, most of the omnipods I purchased were duplicate D omnipods, along with a Prime right torso, and a C right arm for a couple of ballistic builds.
Short to Mid Range
With low, gangly arms, a natural starting place is to explore brawler builds first. In that vein, already knowing that there wasn't a lot of pod space to play with, I duplicated my Loki brawler. Compared to the Loki, this mech loses ECM, which makes it harder to sneak up on people, but sneaking isn't an ideal task for this chassis anyway. All that armor tends to be better used attacking the enemy team's front, so that your team is better able to spread incoming damage, without losing mechs. Even given the different role, this is a reliable (see caveat above) combination of weapons for close-quarters fighting.
In recent weeks--and probably moreso in the near future, given the recent balance changes--the solo queue has been favoring a lot more mid-range standoffs, which can make contributing with a pure brawler difficult in the early part of the engagement. My first adjustment to account for this was to put a smaller UAC in the torso. The UAC10 in the higher torso mount provides a better mid-range option than the low-mounted UAC20. The weight savings provides room for a couple more heat sinks and even more armor, meaning that this build can survive lengthy engagements without ever having to back off to cool. That said, you're gaining sustained damage at the expense of burst damage, and I didn't care for the amount burst damage I had to give up.
The alternative was keeping the UAC20 and swapping out the ER small lasers for mid-range energy weapons. This build maintains much of the burst damage of the ERSL+UAC20 build, instead trading sustained damage for additional range. The ER medium lasers and large pulse laser can be toasty in a close-range fight, so you'll have to exercise some trigger discipline with the energy weapons and make sure the UAC20 is carrying its weight in a close-quarters engagement, but having that huge burst damage available and a laser-based mid-range option works quite well.
You know what other big ballistic weapon works well with a mid-range energy setup? A Gauss rifle. This build actually runs into a different problem: Since all of your weapons are for use at mid to long range, you'll want them all in the higher torso mounts, but your only hardpoint options are three energy spread across both side torsos or two ballistic (one of which will almost never be utilized) in the right torso and one energy in the left. This means you can either have the Gauss rifle and large pulse laser in the torso, while the two ER medium lasers are left shooting dirt from the lowest available arm mounts, or you put all of the lasers in the torso, and you sink precious Gauss ammo into the terrain. As you can see, my choice was to favor the rifle, since it consumes more of the mech's tonnage and space and has a longer effective range than the ER medium lasers.
As with the first close range build I highlighted, I
Remember that wacky ERPPC build with a seven-ton targeting computer in it in the thread soliciting opinions on whether to run the Executioner or the Gargoyle? I kind of sabotaged my success with that build by running a different mech with unquirked, unboosted PPC velocity. Ultimately, I traded the big targeting computer for more heat sinks and armor. This made the projectile velocity more uniform with other mechs, helped the mech run at a much more acceptable temperature, and made the mech more useful, when the engagement range closed later in the match. You'll still need to exercise really rigid trigger discipline, since the initial heat spike from the PPCs is so high, but the ridiculously high dissipation rate from all of those heat sinks allows you to fight for quite a while with the PPCs or the small lasers. Don't fire both in rapid succession, unless something you've just softened with the lasers can be immediately finished off by the PPCs.
Oh, you're expecting small pulse lasers, flamers, and SRMs, right? A build to work at ranges shorter than short range, right? Well, I was thinking of a constant stream of salty, yellow death. This is the build where that Nova comparison that I made in the introduction actually struck me. All of those fixed heat sinks and all of that empty crit space available for more heat sinks means that you can run some otherwise really ludicrously hot energy builds. Five medium pulse lasers will belch out the same damage as a double-tap from a UAC20 at slightly longer range. Yes, that shot will spike your heat by ~40% of your capacity, but you'll dissipate half of that heat, before the lasers recycle. The ER medium lasers give you an option to poke with at medium range, when you can't get the pulse laser arm to clear the terrain, but they are a secondary weapon in a brawl.
Leveling the Executioner was painful, right up until I unlocked Speed Tweak. Hardly any builds felt effective, because the chassis doesn't have the firepower to run up the middle and smash everything in its path, but it didn't have quite enough speed to get onto the flanks, before the enemy team could react. Those few extra kph that come from breaking into the elite tier skills (amplified by MASC usage) added a surprising level of versatility to the Executioner. Suddenly, I could push the center if it was weak or get to the flanks, if that's where I could be of more use. Still, I'm glad to be done with assault mechs for a while now.
A common complaint about the Executioner and other omnimechs with fixed maneuverability equipment (such as the Shadow Cat) is that the maneuverability equipment is wasted tonnage. I tend to disagree, especially on some of the lighter chassis, which turn into ridiculous ninja mechs with high speed and lots of class IV jump jets. On the Executioner, though, some of that tonnage really is wasted. Class I (and II and III) jump jets provide very little thrust, relative to the weight of the chassis that they're mounted on, and class I jump jets eat up two tons a piece. That means that the Executioner is saddled with eight tons of jump jets and can barely gain any more height on a full-burn jump than a similarly-sized battlemech would with a single class I jump jet. Dropping three jets to free up six additional tons of pod space, when you only start with twenty-seven tons, would be a huge boon.
All that said, despite the limited pod space and the pre-mastery teething pains, the Executioner has its place. When it's time to lead a push, an Executioner can get into position faster than anything near its size, before going in to twist and tank all kinds of incoming damage. Getting shots in is great, of course, but what you're really looking to do is draw fire and survive for as long as possible. If you end the match with eighty-plus percent of your health still remaining, then either your team just completely outmatched your opponents, or you did something wrong. Even with the long range builds, by the end of the match, you should be working your way into the fray to take pressure off of your teammates who led and took damage in the initial push.