The combat in Honkai: Star Rail allows you to use up to four characters in a team, and if you've summoned for Blade, you'll most likely be looking for the best team members for him. He's a Wind character following the path of Destruction, and he usually lives on low health because of his abilities.
His Skill, Talent, Basic Attack, and Technique take away a part of his health. If Blade doesn't have enough health to give up, he'll be reduced to one health, which is quite a dangerous spot to be in unless you have some specific characters.
8 Himeko
Himeko might not be a great character for defeating endgame content, but she's one of the best farming characters in the game thanks to her AoE skills and the follow-up attack. Her farming abilities increase even further if put together with Blade since he can remove the Toughness bar of multiple enemies.
If you use his Technique to start the battle or trigger the Talent, he'll deal heavy damage to the Toughness bar of every enemy on the field. Whenever you trigger three Weakness Breaks, Himeko's Talent deals further damage to all the enemies.
7 Luocha
Ever since his release, Luocha has slowly become one of the best healers in Honkai: Star Rail. Apart from his healing, what makes him great is that his Skill can trigger automatically and his Talent field heals every character in the party without using any Skill Point or Ultimate.
Managing Skill Points is one of the hardest aspects of the game's combat, but Blade and Luocha together reduce the attention you need to pay to them. Blade only needs to use a Skill Point every three turns while Luocha doesn't need to use them at all as far as you don't take too much damage.
6 Silver Wolf
Each enemy in Honkai: Star Rail has a certain number of weaknesses, and you can only remove their Toughness bar if the character attacking them uses one of these weaknesses as a combat type. If you have Blade as the only DPS, it can be quite hard to fight enemies without the Wind weakness.
Thankfully, Silver Wolf was introduced quite early in the game, and she can get rid of this hurdle by applying a certain Weakness on an enemy whenever she uses her Skill. This will let you use Blade against any boss enemy even if they don't have the required weakness.
5 Yukong
Yukong is quite a special support character in Honkai: Star Rail since you have to mess around with every character's SPD in your party to make sure that they get a turn after her. This can be quite hard, which is why she performs best if a character can get a random turn in the middle.
Blade can get this kind of turn using his follow-up attack. This attack triggers whenever he loses health in any manner a total of five times. If you see him at around three or four stacks when you get Yukong's turn, you can freely use her Skill to buff this follow-up. The best part is that a follow-up attack doesn't count as a turn for her Skill.
4 Pela
Pela is one of the underrated characters in Honkai: Star Rail since she can decrease the DEF of all the enemies on the field whenever you use her Ultimate. The best part about this is that you don't have to wait for a character's turn to use Ultimates in the game, and you can trigger them whenever you want.
This works well with Blade's follow-up attack since you can see exactly when the attack is going to happen. Time Pela's Ultimate just before the follow-up triggers and you'll be dealing massive damage, especially if you also have Blade's Ultimate ready.
3 Gepard
As mentioned above, Blade loses a part of his maximum HP every time you use most of his abilities, and his health goes down to one if you don't have enough. This can be quite bad since he'd get eliminated if he gets attacked even once, and Destruction characters overall have higher chances of getting attacked.
This can be fixed by using a Preservation character like Gepard to shield him. The hit points of the shield don't count as the character's HP, which means that it won't be reduced with Blade's abilities. Although, enemies might start attacking Gepard here, which isn't good for Blade.
2 Sushang
Blade has a Bonus Ability that heals him whenever he attacks an enemy that already has their Toughness bar gone. This effect stacks up with Sushang if you have her Eidolon one that allows her to recover a Skill Point whenever you use her Skill on an enemy with their Weakness broken.
This leads to her Skill using zero Skill Points overall. If an enemy has both Wind and Physical Weakness, these two can be great for the Skill Point economy. You can even consider using someone like Qingque with them because of the extra SP that you'll have.
1 Bronya
Bronya is one of the Standard Banner characters in Honkai: Star Rail, but she's still great at her job. Whenever her Skill is used, she can give an instant turn to the target character and heavily increase their damage, especially if you pair this with her Ultimate.
Apart from being a good combination already, you can also time it with Blade's follow-up attack to make it even better. Moreover, this combination can be used with Yukong to guarantee that Blade gets to use the buff from her Skill. You'll see him dealing some phenomenal damage if you have both Yukong's and Bronya's buffs.