Luocha is one of the best sustain units in Honkai: Star Rail while Aventurine is an upcoming Preservation unit who fulfils the same role of keeping your team alive and offering utility. If you do not have 5-star sustains on your account and are looking to get one for your account in version 2.1, here are some things you need to know about Luocha and Aventurine.
Luocha vs Aventurine: Who Should You Pull?
Luocha
Luocha is a very comfortable character to use on any account. He offers an incredible amount of healing and is completely SP (skill point) positive. You can run him with a 3-star light cone (Multiplication) and 160 SPD and he will generate you more SP than any other limited sustain unit in the game. If you build some Effect RES, he is essentially immune to crowd-control effects and can cleanse debuffs and remove buffs from enemies.
When compared to Fu Xuan, Aventurine or Huohuo he does not have any buffs or added utility. Luocha's healing tends to be better than Huohuo but you lose out on the added utility the other 5-star sustains have. If your team needs a ton of SP, then Luocha has his niche of being one of the best SP generating sustains in the game.
Aventurine
Aventurine does not have a cleanse like Luocha, nor does he heal. But he is arguably the far better sustain option between the two. His shields are much stronger than Gepard's at the expense of needing SP to generate them. He also grants a massive Effect RES bonus, which greatly reduces the chances of your characters being crowd controlled in the first place.
He has synergy with follow-up attackers and also dishes out a decent amount of damage by himself when he builds up Blind Bet stacks. If you have Dr. Ratio or Topaz, his pull value goes up even more as he has synergies with both of them.
Aventurine does NOT need to be in a follow-up attack (FuA) team to perform
Aventurine is an extremely good sustain unit that can grant you beefy shields that enemies will struggle to chew through. While he does not boast the same level of SP positivity as Luocha, almost all teams can spare one SP every 3 turns to keep his shield active. He also refreshes his shields after launching a follow-up attack so you might not even need to cast his Skill at all in battles where enemies don't do a ton of damage.
Between Luocha and Aventurine, you should go for Aventurine as a sustain unit. But if you already have strong sustain options like Huohuo, Fu Xuan or Gepard and have no trouble beating content, then there is no real reason to go for either Aventurine or Luocha unless you are going for a follow-up team in which case Aventurine is a great pickup assuming you already have Topaz.