Wherever there is life, there is also death, and in Runeterra, Kindred represents the twin essences of death. Lamb grants a quick and painless release, while Wolf chases after those who try to outrun their ends, and these ends are usually violent in nature.
Even the Celestials will eventually run out of time, and when that happens Kindred will be there to greet them, and if they try to fight back, it will be to no avail. Some champions may be able to cheat or circumvent death, but no one is capable of killing death.