Max was created by David Elster to be a younger brother to Leo Elster. After David committed suicide and the synths went on the run with Leo, Max and Leo were the only ones who were not captured.
Max first appears walking on a road in a forest with his synth siblings and Leo. After they are startled by a fox in the woods, Leo asks everyone what their charge levels are, and Max's is at 70% while everyone is else is 30% or below. Leo takes Max with him to get water while instructing the others to set up camp. Max and Leo arrived at an empty camp and saw their synth siblings being taken away in a truck. They attempted to give chase, but ultimately the truck got too far away.
Leo is again with Max, who's doubting if they're actually a family because he was designed to be a way. Leo says his father is dead, and he sees Max not as a design, but as a brother. Just as Leo is about to enter Silas' place, he tells Max that is he says run, or if they discover Max's true nature, to run. After questioning Silas goes awry, Max watches as Leo holds a knife to Silas' throat and makes him tell what he knows about Mia. However, after this Silas elbows Leo back and beats him. Leo tells Max to run, hits Silas in the leg with a wrench, and then runs away himself. Leo takes an alternate route, however, and winds up trapped on a balcony passageway. He slides off over a railing and Max catches him, and leans heavily on Max as they walk away and Silas watches on. Max takes an unconscious Leo to an alleyway, where he rouses him and Leo's first thought is "we have to get our family back" and tries to get up, but Max says they need to take care of Leo first. Max takes Leo to a car yard, as Leo says something's been done to Mia, but Max simply tells him to save his energy. Police show up, and Leo urges Max that they need to go, and after some urging, Max obeys, but they leave behind a sleeping bag. The next day Leo is completely unconscious, and Max uses a bathroom socket to charge Leo.
Leo and Max break into a house, while Max says they need to keep looking for Mia, Leo says they should lie low and do an internet search. Leo then begins to drink, and Max asks why, Leo says "to help me forget", but Max says he cannot forget because is like this. Before he can do much more, the news shows a murder at Niska's brothel which alarms Leo. Leo and Max are at the scene, and Leo concludes that Niska murdered someone. They then meet up with Niska herself, and Max watches as Leo scolds her for taking a life, then as Leo and Niska argue about her leaving. After Niska leaves, Max and Leo return back to the house, and Leo goes to sleep while Max waits by the computer Leo set up to scan for a trace of the synths' unique programming. Max awakens Leo and informs him the search found something, which was a post from Mattie with Anita's root code.
Leo breaks into a car as Max asks whether Mia will be happy to see them as no one seems happy to see them. They begin driving to find Mia, but he says he has a plan to flush them out. He and Max are then at a diner, and Leo jokes that they're an old man, but Mattie appears and reveals herself as the poster. Max slips and asks if Mia is with her, which confuses her, Leo then shows her a picture of Mia/Anita
Max was created as a younger brother for Leo, and his personality, particularly early on, reflects this. He used to be naive and, according to Leo, was unable to take care of himself. He has been very close to reveal his sentience in front of others, something Leo would scold him for. Max also seemed to have a pessimistic streak as well, often thinking their siblings were dead and wondering if they were really family, something Leo would quickly shut down by saying their siblings were alive and they were family.
When reunited with his family, Max can be seen smiling often. He loves his siblings very much, and he even threw himself off a bridge to save Leo even though he would probably be destroyed. Like the other synths, he is protective of Leo, though he will also stand up to him if he disagrees with his actions.
Max has grown a lot as a character. He started "growing up" in season two when he and Leo parted ways and he had to make decisions for himself for the first time. As it turns out, he's quite capable of this. With the help of Flash, Max created a safe haven for conscious synths in an abandoned railyard, and all he wants is for all conscious synths to be able to freely be themselves.
Max seems to be a pacifist, even letting their hostage, who was out to hurt them, go at the risk of his and his family's safety.
David Elster created Max to be a brother for his son Leo, and like the others, Max sees David as his father. Beyond this, nothing much is know about their relationship, but David allegedly used to move quickly from one "project" to the other, meaning he probably spent little time with Max before moving on to make Karen.
They look at each other as brothers, and they're quite close. While Leo will do his best to protect all of his siblings, he is often extra protective of Max, as he is the youngest and used to be quite immature. Max and Leo do have a fall out in season two, but they ultimately reunite.
Mia and Max look at each other as siblings, and they both care about each other, but not much is known of their relationship beyond that. However, Max is the one to convince Matte to save Mia's life by releasing the improved consciousness code to all synths.
Max and Fred see each other as brothers. Max did not want to leave Fred behind, and used quite some time trying to convince the others to take him with them, even though Fred was still under Hobb's control. In the end, he reluctantly agrees to leave Fred behind, but not before pressing their foreheads together and promising him they'll be together again one day.
Max and Niska see each other as siblings, even though Niska initially didn't like the "human words" brother and sister. When they meet up after Niska escapes the brothel, Max doesn't want Niska to leave them again, and when she insists he gives her a cellphone so that they can keep in contact. Niska also donates synth fluid to him when he is malfunctioning, in the hope that it will bring him back.
Max rescues Flash in season two, and afterwards the two strike up a friendship, and creates a safe haven for synths together. Flash once kisses him on the cheek, then immediately apologizes for it and calls it inappropriate, but he reassures her it isn't.
Max and Mattie have had a few friendly conversations, and seem to get along quite well. Max is the one who convinces Mattie to release the code.
Other than Mattie, Max hadn't had many interactions with the Hawkinses. Joe once called the cops on Max and Leo, though he later seemed to regret it. Otherwise, the Hawkinses have helped Max and his family out on several occations.
Max and Hester first meet when he and Leo rescue her, but even though Max initially tries to get aong with her, he admits that the thought of what she might do scares him. They end up falling out when they can't agree on the best way to help the newly conscious synths. Hester later lies to Max on the phone, saying Leo hasn't mentioned him at all, and that they're doing great without him, which adds fuel ot the fire of Max and Leo's conflict.
- Max can once be seen praying to God, even though he thinks God's existence is "highly unlikely".