Good buster team pairing? NA Servers

as the old man in the mountain once said , grab another merlin (pretty sure he was drunk)

Just grab another friend's merlin/waver
That's all Musashi need. Girl got expensive taste after all.

It depend on the situations because u can't use Musashi + double Merlin or Musashi + Merlin + Waver everywhere. If you're fighting strong Rider or archer enemies then you're done. Strong Rider bosses will eat your Merlin/Waver easily and strong Archer bosses will eat your Musashi like it's nothing and you must change your party pretty often into 1-3 turns farm comps because this game is grindy af. Improve and adapt because there are a lot of Buster teams exist out there.
You can even play more defensifely and carefully if you're facing harder contents or challenges or even dividing your buffs and not using all the offensive buffs at the same time for countering Break bars.
Our recent break bars Salter boss is the prime example of that.

Affordable good unit :
- Leonidas for your Buster tank, easy to get, easy to raise and can provide your team with better safety. Good for Harder contents and challenges, he won't dissapoint you.
- Caesar, if you're looking for MASSIVE damage for 1-3 turns. He can provide you with NP Up + Atk Up + Crit Up + Crit star drop rate Up, very powerful steroid.
- Kotaro Fuuma, one of the best Crit star semi-supp with targetable Evade. Along with Musashi Invincibility, fuuma targetable Evade you can save your Musashi or another Buster servant or even your Merlin in the dire times.

More expensive options :
- Quetz can take stars but she's still good for non-crit Buster team. Quetz herself is an amazing Buster servants and outside of taking Crit stars she has party Atk Up and targetable Buster Up buff.
- Elizabeth Lancer, def down + female party atk up with short CD. She's amazing for non-crit reliant Buster team and Lancer atk modifier would also mean she can deal nice amount of damage by herself.
- Helena, a Burst or fast kill support member for Swift kill Buster Crit or general Buster team. For shorter battles she's one of the best ( 3-5 turns ) but for longer battle don't even think to use her, you can still use her for longer battle but it will reduce your gameplay qualities greatly and for that you need to change your teamcomps.
- Jack, one the best Crit star semi-supp member for consistent Crit teams. Remove buff, targetable heal and TONS of Crit stars. She's simply an amazing unit.
- Kato Danzo, come along with Raikou and friends when Shimosa Banner 2 arrives. An SR Kotaro Fuuma, if she's equipped with a 2030 CEs or another Crit star drop CEs you can also have TONS of Crit stars.

Bonus :
My Buster Crit team, Gilgamesh ( main DPS, Knights Dignity/Joint Recital ) + Assassin Scathach ( semi-supp and taunter and Crit star maker, 2030 ) + friends Merlin ( 2030 ).
Leo will be the man to take enemy bosses with ST NP for the 3rd times, kid Gilgamesh/Chloe as my Archer substitute and Hercules for soloing the bosses if all methods are failed or something bad happens.
If i'm going Offensive, i will go all out by using Gilgamesh + friends Merlin + Leonidas + Caesar.
If i'm going Defensive, i will choose Gilgamesh + friend Merlin + Leonidas + Mashu and another backup supp/tank.
For consistent Crit route, Gilgamesh + Hans ( 2030 or any Crit star gen CEs ) or Fuuma or Jack or another Crit star maker + Merlin ( 2030 ). For harder battle, Leonidas is the best Buster tank for now. Here's it if Leo in there, Gilgamesh + Leonidas + Hans + Merlin.

There's so much Buster team out there, don't limiting yourself by just using Musashi + double Merlin or Musashi + Merlin + Waver.
For example, Musashi + Leo + Merlin + friends Merlin + Caesar + Elizabeth Saber ( 2nd DPS, substitute ) + Nero.
Heavy rain of Crit star, Musashi + friends Jack ( 2030 ) + Merlin ( 2030 ). Good if you're dealing with some annoying Rider enemies plus Jack can dishing out lots of damage by herself. If you want your own Crit star maker, consider raising Fuuma or if you want an amazing unit like Jack then you can save your SQ for her.

Lancer infested enemies, Musashi + friends Saberlot + Hans. Saberlot and Hans is a premiere Crit star generator and Saberlot himself is a beast of gameplay, you can expect Offensive gameplay with total destruction here.
Saberlot ( Onigashima 4 Crit stars per turn or any Crit star gen CEs ) + Hans ( any Crit star Gen CEs ) can do the job and can make your saber DPS Crit for almost every turns.

I will remind you something, team comps is situationals and sorry for the longpost, enjoy your time !

Leonidas for 3 turns AOE +25% buster up with 5 turn CD and taunt on skill and NP (NP one gives instant stars even).

Helena, extra AOE 20% charge, AOE up for all cards, buster included, passive star regen.

Waver for easy charges and crit/def/attack bonuses.

Hans, because he's budget Merlin/Waver.

Ofc, other support Merlin is also good, as long as there is no strong Riders who pierce invulnerability, there is no reason to not do that, aside from feeling lazy. Extra bonus if one Merlin has 2030 and the other has Prisma Cosmos =P

I’m in the same boat as you. But yeah it’s pretty much what the other people said above, you can use Merlin, Leonidas, Waver, etc.

....I need to work on my buster teams as well

Musashi wants to pull out her NPBB chain as often as possible. She also appreciates a crit.

So Merlin is obviously the best partner.

Waver is good too, since he buffs attack + crit damage and charges NP.

I feel like I always preach about the Merlin + Tamamo engine but...Tamamo helps Merlin do the two things he’s meant to do faster—spam his NP and use his skills. Merlin helps Tamamo do the only thing she’s supposed to do—spam her NP to help him. Merlin’s uptime on Musashi’s buffs is then a lot better...plus Musashi can charge her gauge pretty instantly and her skills will be off cooldown when you need them. You can also arts chain with Musashi when she needs to. Throw Prisma on Tamamo and have fun.

Hans is a workable budget Merlin too.

But it really depends on what you want to do. NP spam or crit?