Voldemort examines his body and then, pulling a wand out of his pocket, points it at Wormtail and slams him against a headstone. Wormtail reminds Voldemort that he promised something, and Voldemort tells Wormtail to hold out his arm. He pulls out Wormtail's left arm, not his hurt one, and Harry sees the Dark Mark on it. Voldemort touches it and Harry's scar flashes with pain again. As he waits, Voldemort tells Harry that this is his father's grave. Harry hears wizards Apparating. They're all masked and one by one, they kiss Voldemort's feet and then stand in a circle. The circle has gaps as if they're expecting others.
Though Voldemort is inarguably evil, it's telling that he chooses to do something for himself (summon his Death Eaters) before he does something for someone else (heal Wormtail's pain, which he clearly has the power to do). This has the added bonus for Voldemort of impressing upon his followers that he doesn't much care for them as individuals; they only matter to him as long as they're useful.
Voldemort welcomes his Death Eaters and reprimands them for not coming to help him sooner. He suggests that they're now loyal to Dumbledore and one man throws himself forward, asking for forgiveness. Voldemort performs the Cruciatus Curse on the man and turns to Wormtail. He waves his wand, forms a silver hand, and affixes it to Wormtail's wrist. Wormtail kisses Voldemort's feet and takes his place in the circle. Voldemort then greets Lucius Malfoy, asks about his "fun" at the Quidditch World Cup, and asks why he ran when he saw the Mark.
By giving Wormtail this hand and relieving his pain, Voldemort shows that he is capable of helping people--he just chooses not to, and when he does something for someone, it's only as an example. For this reason it's important to recognize that Voldemort does this in front of his Death Eaters, which ensures that they'll see he's capable of being kind and then want to earn favors too.
Voldemort continues around the circle, greeting the Death Eaters and noting who is dead or in Azkaban. At the largest gap, he notes that one "faithful servant" is at Hogwarts. Then, he introduces Harry to the Death Eaters. Lucius Malfoy asks Voldemort to explain how he came back to his body. Voldemort explains that Lily Potter's sacrifice saved Harry but now, he can touch Harry. He demonstrates, which makes Harry's scar burn with pain again. He continues that he lived in forests and possessed animals while he waited for a Death Eater to return to help him. He details what happened when he possessed Professor Quirrell and how he lost out on the Sorcerer's Stone. Then, last year, Wormtail found him in Albania.
When Voldemort admits that he made a mistake the first time around and has since taken action to correct it, it shows that, like Dumbledore, Voldemort is capable of critical thought and of using new information to influence his actions. This reminds the reader that critical thought can be used to create evil, just as it can be used to fight it--Rita Skeeter's smear campaign shows how true this is, given all the people she's hurt with her articles.
Voldemort says that before Wormtail found him, he ran into Bertha Jorkins and kidnapped her. She was able to tell Voldemort about the Triwizard Tournament and, after Voldemort broke through her Memory Charm, he discovered other information. He killed her and invented a spell that returned him to an almost human form. Voldemort explains that to return entirely, he needed his father's bone, Wormtail's flesh, and Harry's blood. Using Bertha Jorkins's information, Voldemort stationed a Death Eater at Hogwarts who turned the cup into a Portkey and made sure that Harry got there first. At this, Voldemort hits Harry with the Cruciatus Curse. The Death Eaters laugh as Voldemort lifts the curse and says that he's going to duel with Harry and then kill him.
The elements that Voldemort uses in his spell to return to his body show that just as Harry is in the process of learning about the past as a way to confront the future, Voldemort also uses the past (his father, an old servant, and his previous downfall) to create a form that will allow strength going forward. Again, this shows that Harry and the side of good aren't the only ones who can use the novel's lessons to their advantage. Voldemort is a part of the world and because of this, he also gets to use what it has to offer.