Although it's only one season into its run, meme-worthy moments, and extreme violence. While the comic series that it's based on has plenty of material for the show to adapt in future seasons, the first season established the dynamic between Invincible (Mark Grayson) and Omni-Man (Nolan Grayson) very clearly.
Nolan is Mark's Viltrumite father, and he is generally much stronger than the half-human Mark, due to his age and years of experience as both an alien warlord and a heroic god among humans. There have been times, however, where Mark has wielded either his powers, his mental strength, or his emotional strength to get the upper hand on his father.
Dealing With The Flaxan Invasion
In one of Invincible's earlier episodes, the true extent of Omni-Man's rage is revealed, as he helps Invincible and the Teen Team fight back the invasion of the quick-aging Flaxans. Throughout the series, both Mark and Nolan have been shown to be at their strongest when they are angry, but Nolan's maddest may be his trip to the Flaxan planet.
The raging Viltrumite makes quick work of the planet, killing countless aliens and destroying buildings left and right in a matter of minutes. Although Mark's rage comes out a little bit in the battle back on Earth, he seems to be able to direct it more positively, which could indicate a more skilled control of his rage than Nolan has.
Cooperating With Cecil
Omni-Man's desire to handle his work alone keeps him not only from accepting help from other heroes, but also from having a good relationship with the powerful Global Defense Agency. Cecil, the GDA's leader, seems to have a particularly unique relationship with Nolan built on fear and distrust.
Although Cecil will probably never trust anyone fully, Mark has proven to him over the course of the show's first season that Invincible can be trusted to do the right thing - most of the time. This alliance with Cecil certainly gives Mark an upper hand over Nolan, as if the latter comes back, the entire GDA will side with the younger Grayson.
Helping Titan With Machine Head
When Titan comes to Invincible for help dealing with the ruthless crime lord Machine Head who has trapped the rocky mercenary in a life of crime, Nolan dislikes the idea at first. He believes that this kind of hero work is beneath Mark and not worth the time or energy it would take to see through.
Mark and Debbie, however, disagree, leading Mark to decide to help Titan, showing a moral fortitude that Omni-Man can't understand, especially given his thoughts about humans in the season finale. Although Invincible is ambushed by mercenaries (including cool villain Battle Beast), he still makes a choice that places responsibility and teamwork over Nolan's arguably weaker ideal of individual strength.
Spending Time With Amber
Throughout the first season of Invincible, Mark tries to spend as much time as possible with his new girlfriend Amber, but his superhero training and duties often get in the way of this relationship. Although Mark isn't always there for Amber, he still tries to be there more than his father wants him to be.
Nolan's relationship with Debbie is, to him, both a necessity in order for him to have assimilated into life on Earth, as well as a potential weakness, as it creates an emotional connection for him. Mark's relationship with Amber, however, defies Nolan's philosophy by recognizing that interpersonal connection is strength, not weakness.
Taking The Punches
The first episode of Invincible sees Mark gaining his powers and training with Nolan for the first time, when Nolan punches him and he struggles to recover. In the season finale, however, Mark takes more than just a punch from Nolan, he takes an unimaginable beating that he nevertheless recovers from.
Even though the final fight against Omni-Man represents major losses for Invincible, including the loss of civilian lives and his understanding of his father, the young hero's perseverance shows strength and growth. His body and ideals are strong enough to stand up to Omni-Man's own.
Working With The Guardians Of The Globe
At the end of the first season, Invincible decides to work with the new Guardians Of The Globe, a stark contrast to Omni-Man who refused to work with the original Guardians. Mark's humility and ability to work with others endears him to characters like Cecil and Eve, but it also gives him backup when he may need it.
Although Invincible may be stronger than almost any other superhero the show has featured so far, there is still strength in numbers and coordination. By understanding that he can be more useful with other heroes than as a singular force, Invincible has the potential to garner more power than Omni-Man's lone wolf style permits.
Battling The Kaiju
Towards the end of the first season, Cecil is doing everything in his power to stop Omni-Man, whose involvement in the death of the Guardians has become more clear. As such, Cecil sends a massive kaiju monster that Nolan had battled before after the enraged Viltrumite in an attempt to slow him down.
It almost works, as it seems like Omni-Man may have been subdued by the pumped-up kaiju monster when Invincible shows up to save his father. Although Mark cannot take down the kaiju by himself, the fact that he's able to save his dad from the massive beast indicates that he is stronger, even if just for a moment.
Appreciating Debbie
During the first season, Nolan's relationship with Debbie is shown to be complicated. The couple clearly love each other, but Nolan struggles at times to respect her thoughts and needs, especially when it comes to Mark's training. In the season finale, this is revealed to emerge from the fact that Debbie's humanity makes Nolan see her as inferior, "like a pet."
There are several times throughout the series, however, where Mark shows not only a genuine respect for his mother, but a concern for her feelings. In seeing his mother's humanity, Mark shows a moral and emotional strength that Nolan cannot grasp: the value of empathy in the face of difference.
Teaming Up With The Teen Team
Mark's collaborations with the eminently intelligent Cecil and the Guardians Of The Globe represent his willingness to and be ed by others, but his early collaboration with the Teen Team during the Flaxan invasion first shows him the value of teamwork. These connections will go on to strengthen his abilities beyond mere strength in numbers.
In particular, Invincible's collaborations with Atom Eve come about as part of this teamwork, giving Mark a person who understands what he is going through besides his father. Invincible, unlike Omni-Man, quickly becomes a hero who not only helps others, but is able to accept help from others, no matter how "inferior" they seem.
Fighting His Father
Perhaps the greatest moment of strength Invincible has comes in the season finale, when Mark's emotional reaction to his dad's betrayal of humanity exploits the Viltrumite's biggest weakness. During his time on Earth, Omni-Man has developed an emotional connection with Debbie and Mark that he does not want to it to.
When Mark tells him that after centuries they will still have each other, though, it seems to get to Nolan, touching him in a way that even he did not expect. Although Mark's reasoning with Nolan about the value of humanity did not work, the teen hero was still able to delay his father's plan through emotional appeal.