In Mahayana Buddhist belief, a bodhisattva is a sentient being who attained enlightenment and buddhahood and was able to pass into the state of nirvana upon death, but temporarily renounced the state of nirvana in order to aid all sentient beings in attaining Buddhist enlightenment. The bodhisattvas are revered as godlike beings within Mahayana Buddhist sects, but are not technically considered gods in the conventional sense, though they might be called upon for aid by practitioners on the path to enlightenment.
The bodhisattva is also the highest ideal for Mahayana Buddhists, who strive to achieve a state of compassion for all living beings and by doing so detach all living beings from the cycle of death, rebirth, suffering, and karma by helping them achieve enlightenment. A key concept involved is the concept of bodhicitta, a state of mind that strives enlightenment and compassion for the benefit of all beings.
I am of the persuasion that, assuming these beings exist at all, bodhisattvas live a horrible existence. They vow themselves to “liberate” all sentient beings, help them achieve the Buddhist idea of enlightenment, selflessness, and compassion for all living beings, and they will pass into nirvana or become Buddhas until this is achieved, but have they realized what this means? Their quest will, with all likelihood, never end. They will never lead all sentient beings into salvation to because living beings are practically endless. Even towards the end of time, there will always be sentient beings who disagree with Buddhist teachings, do not practice the Buddhist ways and ideas of attaining enlightenment, or will not attain the enlightenment that is espoused by Buddhist teachings.
The bodhisattvas would devote the whole of their existence in service of others and have no regard for themselves, because Buddhism teaches the cultivation selflessness and ultimate compassion, and Mahayana Buddhism in particular stresses enlightenment primarily for the sake of others and saving all living beings. Obviously the bodhisattvas would not feel any unhappiness or dissatisfaction from this because of the state of mind they have cultivated, but I find an existence where you basically spend all eternity trying to save all living beings and living my life for the sake of everyone’s salvation would be undesirable, unfulfilling, and nightmarish. Imagine living a life where you acted only in service of the people and having no regard for what you wanted or what you felt was right. What if you realized your quest could never be complete? What if you came to the conclusion that you couldn’t help everyone, for there will always be someone in need that will end up going without your service? Or if that the people would never be happy with your efforts, always demanding more?