Many people have got many gifts from gods to protect them from being killed, or to serve them. Here are some names of those people.
Baali and Sugreev were two brothers (in Raamaayan times). Baali had a necklace of jewels from his father Indra Dev to be undefeated in the battle till he had that necklace in his neck. he had a boon also from Brahmaa Jee that whenever he will be in the battlefield, he would draw half of the physical power of his opponent, thus increasing his own power and reducing his opponent's power. For the same reason it was impossible to kill him. That is why Raavan who had the boon to defeat everybody could not defeat Baali. It is said that for the same reason, Raam had to kill him from hiding, and unfortunately his necklace also broke before Raam shot His arrow at him.
(2) Madhu Daitya
There was a Daitya named Madhu. Once he performed penanance for Shiv Jee and received a Dand (scepter) from him, that nobody else will be able to kill him till he had that Dand in his hand. When he died he gave that Dand to his son Lavanaasur. When Shatrughn was assigned the duty to kill him, he had to watch the time when he was without that Dand. One day Lavanaasur went out to collect his food without that Dand and Shatrughn got the opportunity to kill him.
Satraajit, the father of Satyabhaamaa, once performed penance for Soorya Dev and got a gem from him - Syaamantak Mani (gem). That gem would give him lots of gold daily. Its condition was that he should keep the gem in a clean environment and use it for welfare work, otherwise it will destroy the wearer of the gem. He kept in clean environment and spent that money for yagya and for his public. Once he gave that gem to his brother Prasenjit to wear. he went to forest for hunting wearing it and could not maintain its clean environment and was killed by a lion.
(4) Kaartveerya Arjun or Sahastraarjun or Sahastrabaahu
Sahastrabaahu, the son of Kritveerya, performed the penance for Dattaatreya Jee and got a garland from him, along with other boons. Till that garland was in his neck, nobody could defeat him. That is why Raavan who had the boon to defeat everybody could not defeat Arjun.
Once Raavan lifted Kailaash Mountain in great anger. As he lifted it, it shook. Shiv and Paarvatee were sitting there. Paarvatee asked - "Prabhu, What happened?" Shhiv Jee knew what had happened, he just pressed the Parvat with the smallest finger of his left foot. This made Raavan's arms pressed under the Mountain and he could not take them out. He stayed in this situation for about 1,000 years and continued to cry. After 1,000 years Shiv kindly released him. Since he continued to cry (Rotaa Rahaa) for all those years, Shiv gave him the name of Raavan. Later he gave him a sword too, named Chandrahaas, although it has never been mentioned in Raamaayan after that, that he used it anytime.
Karn, son of Kuntee, was a threat to the life of Indra's son Arjun. To save his son Arjun, Indra decided to ask Karn's Kavach (armor) and Kundal (earrings) in alms, because everybody knew that at the noon time Karn used to give alms and everybody got what he wanted. karn never refused to give anything to anybody. So Indra went at the same time to ask for his Kavach and Kundal. Karn was born with them and they were his life savers. In spite of being warned by his father Soorya Dev, he did not move from his path of truth. Then Soorya Dev suggested him to ask for Indra's Power. So that is what he did.
After donating his Kavach and Kundal to Indra, Karn asked his Power. Indra gave that Power to him with the condition that after being used for once it would come back to him. Thus Karn got the Power from Indra. Although he asked it to kill Arjun, but he had to use it on Ghatotkach at Duryodhan's suggestion. Thus Ghatotkach was killed by that Power and Karn lost the power of his survival.
When Yudhishthir, the eldest Paandav, had lost everything in the second Dice Game and had to go in exile, many Braahman who were dependent on him, also followed him. It had become impossible for him to feed them and to take care of them He tried to explain to them that he was not the king and he could not take care of them, so they should look for some other source, but they insisted that he was the only king for them and they would not go anywhere leaving him like this.
This made Yudhisthir worried and with the suggestion of Rishi Dhaumya performed penance for Soorya Dev and received an Akshaya Paatra from him to maintain innumerable people from it. Soorya Dev said - Take this pot. It will give you as much food as you will want from it - all kinds of food, but only till Draupadee ate from it." Yudhishthir used that pot throughout his exile period, and there was never any shortage of food in his Aashram, of course till Draupadee ate.
Thus all these people were given some kind of gifts which made them either rich or invincible in the battlefield, or able to do welfare work for people.