score:10
This is a fundamental premise of Mayayana, that the goal is not to be extinguished and leave samsara like an Arhat, but to stick around until everyone is enlightened.
Here is the zen formulation of the Bodhisattva Vow (couldn't find the Tibetan version)
Beings are numberless; I vow to save them. Delusions are inexhaustible; I vow to end them. Dharma gates are boundless; I vow to enter them. Buddha's Way is unsurpassable; I vow to become it.
As for where one is upon enlightenment, there are more lots of formulations, I don't have a good idea on how to summarize them.
Upvote:0
Mahayanas say that if you ask your teacher to come back, he can choose to come back out of compassion, he doesnt have to, he does to help sentient beings.
Upvote:2
If I can add just a little more detail - the Dalai Lama is an emanation of AvalokiteΕvara, the Bodhisattva of compassion. As @MatthewMartin said - AvalokiteΕvara will continue to come into the world as long as there are unenlightened beings to help.
Interestingly AvalokiteΕvara also eminates as the Karmapa and other Tibetan lamas so presumable can co-exist.