Liz’s kit seems tailor-made for Koyanskaya teams. Ramping steroids on NP? Check. Stackable skill-based buff? Check. 30% battery on a 5-turn CD? Check and then some. Koyanskaya/Liz/Koyanskaya/Oberon will be Liz’s best team for anything blitzable. With a 50% charge CE and Mana Loading, Liz is guaranteed the loop here. Turn 1, Liz uses her own battery. Turn 2, the Koyanskayas use theirs. Turn 3, Liz uses her battery again, and Oberon plugs in to use everything he has available. You also have either guaranteed crits on turns 1 and 3 or nearly guaranteed crits on all three turns (depending on when you use Koyanskaya’s second skill).
Liz also has good enough cards that, especially with Koyanskaya’s help, she can realistically tri-loop with Black Grail as well. She needs to refund either 20% on one turn and 30% on the other, or 50% on either turn, both of which are entirely possible with crits and Koyanskaya’s Buster charges. You can also use Nobukatsu to make this easier if you have Mana Loading on him or an MLB Kaleid lying around, since he can use his NP after Liz’s for a free extra 20% charge, on top of some other nice buffs.
Liz doesn’t need optimal setups to be good, though. Liz’s tools are generically strong enough that she can work in whatever Buster setup you want to run her in. She’s a solid point Servant for Himiko/Castoria teams, for instance, with her self-protection, frequent charges, and good damage. She can also work in Merlin-centric teams, especially since her battery-plus-star-burst sets her up perfectly for Hero-Creation-fueled NPBB chains. While Liz’s kit is highly optimized for Koyanskaya setups, she’s more than sufficient for older styles of Buster play.
She struggles a little more without any native SSR supports, but she’s still a self-sufficient damage-dealer with strong skills. If you have no SSR supports of your own, considering bringing Hans alongside a friend Merlin. Hans provides 15 stars per turn, which is nearly enough for Liz to flood the field with just her third skill. Hans and Merlin collectively should let Liz NP regularly while also supporting her Buster crits.
If you have Koyanskaya and Oberon, I’d strongly suggest giving Liz The Black Grail for maximum burst power. It may require retrying a fight on occasion if you roll, say, all Koyanskaya cards on a turn, but the extra firepower is well-worth the cost. In less optimized teams, staring NP charge CEs are a good pick. Aerial Drive, in particular—which gets a rerun in Liz’s own event—fits really nicely with what Liz has on offer.
Notably absent from Liz’s kit is crit damage. As such, Crit damage CCs are an excellent pick here, since Liz has trivial access to crits and will enjoy the extra damage. Mage of Flowers is also a good choice here if you have Liz’s optimal supports, as the extra 10% NP charge can solidify Liz’s NP gain. I’d put it either on Liz’s Quick, to offset her weakest NP gain card, or on one of her Busters, so you can hit the 30% charge threshold with just a single card.