In fact, Sarek plays a large part in the Homeworld Story, which is 56 pages long. For those who have not read this comic, I must warn you that I will be going to go over the entire plot from this point forward.
The story begins with Sarek, Lar'tok, and her aide Ku'bik meeting in a large building (possibly royal headquarters) in New Ketira. Lar'tok speaks to Sarek about how happy she is about his presense, and that he will be part of New Ketira's official admission into the Federation. She feels that they owe Sarek an "incalculable debt", as there would be no New Ketira if it were not for his intervention ten years before. He states that he was merely doing his diplomatic duty.
Lar'tok jokes frequently with Sarek, but is always very respectful. She beckons for him to follow her, so that he may meet her successor, Shiel'kia. Sarek was not aware of her stepping down, and tells her so. It is then that she informs him that she is dying.
Sarek attempts to remain calm, so that his surprise and distress does not show.
Lar'tok makes a remark about Vulcans and their "emotional scenes", which I found very amusing.
She explains to him that her impending death is entirely natural, as she has lived a century and a half. Now that she is going to see New Ketira join the Federation and everything is in order (and she has seen her friend Sarek again) she feels that it is an appropriate time to "make an exit".
When Sarek questions whether or not this is suicide, she explains that her species, after a certain time, are able to select their time of death. The Katiran's decision will begin an irreversible chemical process, which triggers hormones that bring death.
Sarek is not relived, but he understands.
They approach Shiel'kia, who turns and bows to Sarek, honored to meet such a man. When Sarek mentions her being Lar'tok's successor, she turns to Lar'tok and reveals that she does not wish to "blend" with her and lose her individuality. This upsets Lar'tok very much, as without the blending she cannot lead. Blending would mean that all previous leaders would be a part of her, and so she renounces her position. Unfortunately, she had been groomed for five years to lead, and there is no time to find another successor before Lar'tok dies. Shiel'kia begins shouting, and is very adamant about remaining an individual.
Jumping to a later date - the Enterprise is escorting Sarek to the ceremonies admitting New Ketira into the Federation. It is during the briefing between Kirk, Spock, and McCoy that more information is brought foreward about Sarek's role in Ketira's history, and about the "blending".
Spock explains Ketiran blending to be, in a way, like the Vulcan mind meld. Memories are transfered from one "sensitized Ketiran mind" to the other - by doing this, a new leader is "endowed with the accumulated knowledge and experiences of her predecessors".
Spock also explains that Sarek's involvement with the Katirans began in a time before Sarek and Amanda's marriage. While Sarek was acting as mediator between Arvaga and Delta Veylos, he encountered a small community of Ketirans led by Lar'tok. The Ketirans had been dispersed from their original homeworld in a war a couple of millennia before. They were then doomed to wander the galaxy - facing persecution, their numbers dwindling. Sarek brought this matter to the attention of the Federation, and a suitable planet was found for their colonization. This planet become New Ketira. Other surviving groups of Ketirans were later found and settled on the planet afterwards.
Lar'tok chose not to join the federation at that time, because she wanted Ketiran society to develop and prove itself worthy of membership. The Ketirans eventually built an extremely successful society built on trade, and believe that their world should be a haven for other outcasts, as it had been for them.
Kirk, Spock and McCoy beam down to meet with Sarek and Lar'tok.
Lar'tok tells of how she naively thought that the scattered survivors would all come together on the new planet and "melt together to recreate the Ketira of old". This did not happen, however, due to idealistic differences. Many of the survivors, depending on their experiences during the two thousand years of wandering, returned with very different ideas and lifestyles - many even looked entirely different. Ketirans have the ability to alter their appearance to a certain degree - size, body shape, type and color of hair and skin, and some facial characteristics. They can then pass these changes on to their offspring.
Shiel'kia walks in on the meeting, and announces those who look no different from Lar'tok have also changed. This upsets Lar'tok, as Shiel'kia was not invited to the meeting due to her renouncement. Shiel'kia gets very worked up, exclaiming that she has grown up in a world full of diversity, and that diversity is the way of the future. When Lar'tok tells her that one must understand the past in order to deal with the future (hence the blending), Shiel'kia exclaims that the blending only binds her to the past.
Lar'tok is overcome and falls to the ground, hand to her chest. The stress of arguing with Shiel'kia caused her body to react defensively by shutting down temporarily - thus conserving what strength she had left and holding off a potentially fatal overload. Shiel'kia is worried, but still will not cooperate and runs off.
Lar'tok, when conscious, realises that Shiel'kia is frightened, as she was frightened herself when she had only to lead a small community in the past.
Kirk is then notified by Scottie about a fleet of nine ships which appeared out of subspace, asking to speak to the captain of the Enterprise. They are Ketirans, and they call themselves the Sancti.
Part two coming soon.
Note: they keep forgetting to color Sarek's eyebrows. This distresses me.