Leavanny, surprisingly enough, is an extremely powerful Striker for sweeping through the Battle Villa thanks to its powerful toolkit allowing it to function perfectly fine without its Trainer Moves. Because (thanks to its Passives) it has no need for Mp to to buff up and deal great damage, Leavanny is the Battle Villa damage dealer Sun users have been waiting for and the perfect Striker for this team. Fortuitous, On A Roll, and Swag bag combine with Silver Wind, Bug Buzz, and Speeding Sun to quickly snowball Leavanny into a monstrously powerful damage dealer with the bulk to make it through Aoe (and that’s before even factoring in skills like Beffudle, Trip Wire, Grand Entry, and Charging Sun depending on your grid). In terms of its practical use, Leavanny has very little to do in most matches past spamming Silver Wind and Bug Buzz and watching the buffs pile on, but this does beg a very important question: which move should be used when? In general, using Silver Wind until Ho-Oh’s Sync Move, and switching to Bug Buzz after Sync to start piling on damage should give you the best balance between buffs, debuffs, damage, and Sync speed. So far as how you should Grid Leavanny, the options available are too numerous for me to give you one definitive answer but I’ll run down the key skills to consider here: Charging Sun, Grand Entry, Trip Wire, On A Roll, Swag Bag, Silver Wind Unfortuitous, Move Gauge Refresh, Fortuitous, Solar Flare, and Healing Sun.
Ho-Oh has exactly one (fairly self-evident) role on this team: put up Sun as fast as possible, and then sit around until the next match to do it again. There is very little else to say; Sun is what allows Vileplume and Leavanny to become the unkillable monsters they are with Healing and Speeding Sun, and Ho-Oh is the only pair who can set it without losing Mp. Your early game goal when piloting this team should be reaching Ho-Oh’s Sync Move as fast as you possibly can to activate your other pair’s Passives, and once that’s done all Ho-Oh needs to do is act as a second meat shield for Leavanny and stay alive.
Vileplume is the team’s resident tank and status spreader, and its Piercing Gaze Stun Spore combined with Healing Sun later on is a big part of this team’s sweeping power. Because those two abilities are, again, free of Mp restrictions Vileplume is able to reliably maintain the team’s survivability across several BV Stages. Beyond just Paralysis and sheer bulk, Vileplume also has access to a pair of extremely potent buffs (one of which has Mp Refresh access), allowing it to reach a whole other level of defensive power against multiple Stages a day. On top of all of this, Vileplume’s grid even offers free Confusion spread through Flabbergast, as well as a potent debuff in Satisfied Snarl. When it comes to Vileplume’s practical use, using Stun Spore to as many pairs as possible as often as possible, with a buff or two thrown in against harder stages, is the way to go. This method even provides consistent Healing, since by the time Sun has been set you should be sweeping through opposing pairs and having to apply Stun Spores to their replacements.
An example Sync Grid for a Vileplume used on this team can found here:
Discussion: How to use this Team
Because this is a sweeping team and situations differ based on your pair’s health and Mp, I can’t give you an exact table of moves to map out your early game. What I can do, however, is give you a general framework that combined with your own common sense and another strong BV team or two should let you fully clear in just a few days. Early on, your main goal should be reaching Ho-Oh’s Sync Move as fast as possible to collect those sweet Healing and Charging sun bonuses. How you’ll want to go about this is by spamming SIlver Wind and Stun Spore as hard as your Move gauge will let you until your Leavanny has reached a good amount of buffs and all three opposing pairs are statused. From here, you’ll generally want to switch to Bug Buzz and Energy Ball (for Healing Sun, although you should still be using Stun Spore on every new opponent) since Speeding Sun will eliminate your gauge issues. That should give you everything you need to take this team into the Villa and get sweeping, but even though this goes without saying do remember to proc “Pour It On!” once or twice against Physical Stages so you don’t get bopped before your Sync Move.