I told you I named one of my Nova's "Capella". We'll get to that build.
General Notes & Caveats
With the Novas, watch your omnipod selection, including the center torso. Unlike most Clan omnimechs, the Nova's quirks are quite substantial, so tuning your omnipod selection can have a noticable effect on the mech's performance, even when you don't have weapons mounted in the particular location that you're altering. By way of example, on one of the builds highlighted below, I moved the lasers from the right arm to the left arm, because the B right arm omnipod has a quirk that reduces the jam chance on the UAC that's shoved in that build's right torso. If you decide to replicate these builds, check the omnipod quirks.
The other big thing to point out is that people leg Novas. I don't know why. It's got a huge center torso; it's not particularly fast, and the durability quirks on the legs are actually larger than the durability quirks for the torso sections. Despite that, people aim for the legs, so most of the builds that I have highlighted have been slightly updated since I originally saved them to shift more armor off the head and back and unused arms and onto the legs.
What Builds Don't Work at All
The Nova is a chassis that is ill-suited for ballistic builds. It's got omnipods with ballistic hardpoints for both arms and side torsos, and its arm omnipods have amazing quirks for ballistic weapons. With a fifty-ton chassis, you'd think that a dual-UAC5 build would a go-to build, but it won't work. Each side-torso comes with two fixed heat sinks, and the mech has five fixed jump jets elsewhere. This takes up so much tonnage that you can't reasonably fit two UAC5s with enough ammo to last through a good match. Fitting a Gauss Rifle or a UAC20 and a cursory amount of ammo doesn't leave enough room for anything else.
More obviously, there's also no such thing as a purely missile-based Nova. Only two omnipods have missile hardpoints, and each of those only has a single hardpoint. That's not enough launchers for a pure splat build or a useful cluster of LRM5 launchers. Again, there's some nice quirks on the missile omnipods, but you'll need to make mixed builds with other weapon systems.
What about mixed ballistic-missile builds? These run into the same problem that the pure-ballistic builds that the pure ballistic builds run into--there's not enough weight for your weapons and ammo. A combination of a UAC10 and two SRM4 launchers leaves only enough weight for about 800 damage worth of ammo, and a longer-range build like a UAC5 and two LRM5 launchers can't belch out damage fast enough. If you could drop the four fixed heat sinks and a couple of the jump jets, you'd probably have some really great options.
Mixed Energy Builds
I've highlighted on other chassis and in the Clan tech thread that a really great option for Clan chassis to add to their short-range damage potential is to use the omnipod system to build a cluster of six energy hardpoints and slap in six ER small lasers. With the Nova, that just means using a prime omnipod for either arm, which means that you have the rest of the mech and another twelve to fourteen tons to play with.
Since there's not a lot of free tonnage and we're already using ER small lasers, SRM launchers seemed a natural companion weapon. As with the similar SRM/ERSL Loki build, this build has mixed results based on whether or not the enemy team lets you get behind them. Unlike the Loki, the Nova cannot mount ECM to help it sneak about, so life is more difficult in this build. You either need to swing really wide (which is more difficult in the Nova than in other medium mechs, due to your speed) or stick with your team's main line and hope they push aggressively. Before I get lost in a rant about the aggressiveness about pugs, let me just say that this build is not Capella, and Capella is better at doing what this build does.
You know what? Screw missiles. I like autocannons. This build gives up a little bit of burst damage potential in trading the SRMs and some heat sinks for the UAC10, but it gains a weapon that is reasonably strong at mid-range and close-range. This means that, when you're rolling with the main line of your team, you can contribute to the fight, even if the team stalls 500 meters from the fight. With the B variant's right arm, you stack the deck in your favor on your jam chance rolls, so if you're running hot, you still have a reasonably reliable means of dealing damage. I've had a lot more success with this build and will be keeping it available for future use, but it's still not as good as Capella.
Pure Energy Builds
To the great surprise of nobody, the Nova is an energy chassis. It's quirked for energy weapons; it's got loads of energy hardpoints; it's short on tonnage, and it's got loads of heat sinks built in, whether you want them or not (so you may as well use them).
A particularly popular build for the Nova is the dual-ERPPC sniper. I haven't had a whole lot of success with this build, but that's more a pilot failure than a build failure. It's been some time since I last ran a mech with PPCs as its primary armament, and my play time with the Novas has been somewhat sporadic and disjointed, so I just don't have my eye in for the lead angles.
ERPPCs are wicked hot, though, even with an omnipod layout optimized for PPC use. The old solution of switching to large pulse lasers fixes some problems, while introducing others. On the one hand, the mech will run a lot cooler, but on the other, the unquirked beam duration of large pulse lasers means that as a sniper, you're leaving yourself exposed to return fire for quite a while. More than that, it's easier to trace a beam back to its source than it is with a PPC projectile, meaning that the light mechs on the enemy team will have an easy time hunting you down.
But neither of these is Capella. The following is Capella....
Eighty Sathanas Juggernauts Blowing up a Goddamn Star
What's the common element to each of the mixed-weapon builds? Six ER small lasers on one arm. What pairs well with six ER small lasers? Another six ER small lasers. And with that said, this is Capella.
A caveat: Twelve ER small lasers fired at once triggers enough ghost heat to immediately shut you down. Alpha striking in this mech should be treated as it is in BattleTech fiction: It will be your last shot in a fight, whether because the heat kills you, because the shutdown lets your opponent kill you, or because the sixty damage burst is enough to finish your target. Most of the time, you'll want to fire your left arm lasers, followed by your right arm lasers, near the end of the beam duration of the left arm lasers. (Reverse the order, if you're peeking around a hill that exposes your right arm first.) Keep a chainfire group set up, just in case some cheeky light thinks it can shut you down with flamers.
I mentioned that Capella does everything the mixed SRM-ERSL build does and does it better. That's due to the fact that the two builds can burst similar amounts of damage, but the short duration of the ER small laser means that you can more easily focus that damage on a single component, while SRMs, even with Artemis, spread at least part of the volley to neighboring components. The precision makes it much easier to pluck the legs off of fast mechs and get quick torso kills on larger, slower targets. Six more heat sinks also ensures that Capella can cool down faster and more rapidly fire, when its at the top end of its heat capacity, and unlike SRMs, lasers deal partial damage beyond optimal range, meaning that you've got some ability to project damage into medium range fights.
Capella winds up performing a lot like the large pulse Swayback (which has clearly earned a name that I haven't yet given it). If you put it in the right place, it gets 500 damage and two
The Nova's chief weakness--and the reason I sat on the loyalty variant for so long, before finally deciding to build out three variants--is that it doesn't offer a lot of variety. The fixed equipment and consequentally small amount of usable tonnage dictate the use of energy weapons. The available hardpoint configurations dictate clusters of ER small lasers. The way Clan mechs generate and dissipate heat, even with the Nova's mitigating quirks, further dictate clusters of ER small lasers.
If you go whole-hog with ER small lasers, then you get a great mech, and there's a couple of workable options that only partially commit to ER small lasers. Unlike other chassis, particularly omnimech chassis, which can reward experimentation with an oddball build that outperforms expectations, the tonnage restrictions on the Nova leave little room to experiment.