[Reborn + brainless feel-good power fantasy + System + no angst + loyal brothers + well-rounded protagonist] He Yuan, an animal caretaker at Huacheng Zoo, accidentally witnessed a poaching gang smuggling a nationally protected Class I animal in his previous life. While fleeing, he fell off a cliff. When he opened his eyes, he discovered he had been reborn! He had also obtained the unstoppable Great Shun Life System.
Oh, so you want to poach animals? Perfect. I'll get my brother a first-class merit award!
Oh, you've got your eyes on my zoo's land? Let's see if the whole city agrees!
Oh, your circus doesn't want the animals anymore now that they're old? Hand them over! I'll take care of them in their old age!
(Updates whenever inspiration strikes. Amateur author.)