Lopunny:
Pretty self-explanatory set with the added boon from Encore I outlined earlier. The AI heavily favours switching out of any non-attacking move they've been Encored into that is not Protect, even stat-boosting ones. This is obviously a great advantage, as you can render one side of the field incapable of doing much of anything for a couple turns. There are rare occasions where a switch won't happen - I assume because said switch-in fares poorly against whatever attack was used on that slot prior, or something along those lines. I still haven't encountered enough of these situations to properly test, so if anyone has additional thoughts on the matter I'd love to hear them.
Limber is the not entirely worthless base Ability that may prove useful from time to time; if there's a possibility of Thunder Wave but you don't want to switch in Fini immediately, or if you want to Fake Out an Electrode without the chance of Static triggering, for instance. It's fine to try this if you don't require any of the Mega form perks in Scrappy, more oomph behind Fake Out, additional Fighting type, or +10 to Defense straight away.
Landorus:
As you might have noticed, this team was quite similarly modeled after
turskain 's Golisopod squad, especially with the early Azumarill version and now with an identical Z-Aegislash. After seeing his success with the Incarnate forme in the Maison and consequent solid performance crossing over to Tree, I wanted to try him out for myself. He ticks a fair few boxes - two immunities in Electric and Ground, excellent power thanks to Sheer Force, solid coverage options, Earth Power doesn't require teambuilding around EQ synergy and perhaps most importantly, 101 base Speed. That could be viewed as a trollish tier, but I'm certainly not complaining. HP Ice seemed a bit too good to pass up on, the last moveslot was up in the air between Sludge Bomb, Grass Knot and Psychic. Grass Knot appeared to be very mediocre after running calcs on what I needed to hit with it, while Psychic seemed a tad unnecessary with having two Fighting resists and an immunity already, and Fini threatening with Moonblast as well. I settled with the Poison coverage and have been very happy with my decision; it OHKO's all Whimsicott/Shiinotic without making contact, which is great since Landorus does not have the luxury of Misty Terrain protection due to being airborne. It also fills the previous void of not being able to hit the Rotom forms (apart from Mow) for any types of damage, with a 90% chance of 2HKO'ing the HP-invested variants.
Tapu Fini:
Scald and Moonblast for reliable STAB attacks that don't harm my allies. Protect in this instance was entirely worthy of a moveslot, but it took me a while to decide on the last; Ice Beam sounded OK to kill x4-weak things that wouldn't die to Moonblast, despite being redundant coverage otherwise. Heal Pulse, Haze, Calm Mind I also considered, but none sounded like they would translate well to Tree Doubles. I settled for Taunt in the end to further cut the usefulness of sets relying on passive strategies, and as a secondary TR stop against mons not called Aroma Veil Aromatisse or Oblivious Slowbro/King. Taunt and Encore also form the OP 'TaunCore' disruption strategy - the rare scenario where you have nothing better to do than force something to start Struggling to death rather than attacking. I've only used this once so far against a Blissey, which did actually die quicker thanks to Struggle.
The HP investment maximizes Leftovers recovery, and along with the SpD EVs enables Fini to tank strong special hits like M-Alakazam/Specs Alakazam Psychic, Sheer Force Earth Power from Landorus-2, Tornadus' Hurricane etc., all of which are 3HKOs after said recovery. Don't have to worry about Hurricane confusion either! Modest and 188 SpA means Fini can OHKO frail mons like Noivern, Infernape, Talonflame etc. 100% of the time with its respective STAB attack; the cut from max SpA didn't appear to alter anything important, at least not for this particular team. 12 Spe sits Fini at 107 Speed, one point above all the uninvested Rotom forms.
Aegislash:
I copied turskain's set for this - survives Landorus-2's Sheer Force Earth Power from full HP barring no CH. Ghost/Steel is pretty good coverage, only missing out on a couple things neutrally. I don't need to explain much here, but Wide Guard is really, really, really good. Aegislash can just sit there spamming the move while the AI adamantly Blizzards/Surfs/EQs/Rock Slides to no avail, shielding himself and his ally from harm in the process. There's been times where I leave a Milotic or Garchomp alive on purpose as it repeatedly goes for the spread move, just to witness the AI's team gradually get destroyed by friendly fire. Never-Ending Nightmare provides great onetime power and is a significant improvement over Leftovers; OHKO'ing a Slowking/Bro or other TR setter before they're able to set it up is a pretty good feeling.
I'll just mention at the end here that not only are Fini and Aegislash fantastic switch-ins for Lopunny and Landorus, they also synergize very capably with each other, forming this stellar defensive backline that is difficult to break through. There's been a handful of battles already where my leads are immediately switched out for Fini/Aegi, and the AI simply does not have enough firepower to break through the core, with or without Wide Guard's help. The learning curve I mentioned earlier revolves around playing smartly with Lopunny and Landorus though, with neither having impressive bulk to take hits; especially with the bunny, preserving in the back for a second Fake Out or more Encore shenanigans is often key to getting the most mileage out of her.
