
Gothorita
Traits: Frisk / Shadow Tag
60 / 45 / 70 / 75 / 85 / 55
Compared to Gothitelle:
-10 / -10 / -25 / -20 / -20 / -25 / -10
At first glance, Gothorita seems like a terrible choice for a pokemon (even in NU). However, with Gothitelle banished to the BL, Wynaut just being bad (especially with encore nerf), Gothorita rises as the best user of Shadow Tag in the tier (arguably up to UU).
Is Gothorita viable? I think it is, despite the significant drop in bulk and power and small drop in speed. I believe its best set is as follows:

Gothorita @ Choice Specs
Trait: Shadow Tag
EVs: 252 Spa / 4 SDef / 252 Spd
Modest Nature
- Psychic / Psyshock
- Thunderbolt / Energy Ball / Dark Pulse
- Shadow Ball / Energy Ball / Signal Beam
- Hidden Power Ground / Hidden Power Fighting / Hidden Power Ice
Gothorita's job should be to come in safely, either off a death or slow Volturn, sleeping pokemon, encore, whatever, and take out the pokemon. The best usage would be to take out the Alomomola / Amoonguss core with Psyschock and Thunderbolt, to take out any threat your team needs taken care of. (For example, HP Ground will make quick work of Bastiodon for Swellow).
Each coverage move has its own merits, and basically any decent special attack is useful if it can take out something that threatens your team. Energy ball is great for Golem (with hazards support), Signal Beam for Exeggutor.
As for other options, a Choice Scarf / Trick / CM set might seem viable, or an eviolite set, but I think that the lack of power hurts (as I thought with Gothitelle as well. The speed is not needed, the power is). Gothorita derives its usefulness from basically being able to say "I want that one gone", and going out and doing it. With 20 less Spa, 252+ and Specs are necessary to KO threats. Proving me wrong on this would be nice though :)
Here is a calc to show Gothorita's effectiveness.
Gothorita@Choice Specs (252 EVs, +Nature) Thunderbolt vs Alomomola (252/4 EVs, Neutral Nature): 82 ~ 96.6% (438 ~ 516 HP)
It misses the OHKO, which is the huge downfall of Gothorita. However, A 2HKO is guaranteed and not bad, because the worst Alomomola can do is crit waterfall or Toxic. Gothorita can still KO pretty easily anyway since it isn't hard to bring Alomomola down to 82% health. Spam some physical attack as they switch in Alomomola to sponge it, then bring in Gothorita to KO.
My calc wasn't really working for Amoonguss (it was saying Psyshock did less on special variants? although most Amoonguss are physically defensive), but I assure that Psychic and Psyshock will do a good chunk (once again not KOing, but depending on the set can OHKO). If someone could run some calcs that would be great (or recommend a good Gen 5 calc?).
So what do you guys think? How viable is Gothorita? Are there other sets that are as effective as the Specs set?