There is nothing Lan Wangji can do but pull Magnus up, easily enough with their hands still linked, and fold him into a proper embrace, Magnus' head tucked into his shoulder and both of Lan Wangji's arms around him. It's a little less tidy than those first two, outside on the grass, because Magnus' face is so damp already and because of the way they're sitting, but Lan Wangji doesn't allow that to deter him. He cannot promise not to die. Magnus has seen him in battle now, and knows that he would be very difficult to kill -- but that is no guarantee, and Lan Wangji would prefer not to make promises he can't be sure of keeping. So he only holds onto him, steady.