Mikael

"Nobody cares about you anymore, boy. What do you have? Other than those whose loyalty you forced. No one. No one." -Mikael to Klaus in Homecoming episode.

Mikael was an Original Vampire who was once a wealthy landowner in a village in Eastern Europe. He is the patriarch of the Mikaelson family. He was the father of Elijah, Finn, Kol, Rebekah and Henrik and the step-father of Niklaus. He was in his late 40's to early 50's, and was seen to be strong, controlling, domineering, strict, and authoritarian in nature. After moving to the New World, his wife bore six children and his family was quite close, though he and Klaus didn't get along well at all, due to the fact that Klaus was not his son and was from a Werewolf Bloodline. His wife had been unfaithful many years before and when he found out about her affair, he hunted down and killed Klaus's father and his entire family, not realizing that he was igniting a war between species that rages to this day, the war between the vampires and the werewolves. Mikael was the one who asked Esther (wife) to turn the family into vampires. 

In Homecoming, Mikael helped Elena and the Salvatore Brothers to lure Klaus to him so he could kill him for good. To do this, Klaus needed to think that Mikael was dead, so Elena temporarily daggered him and later revived him. When Mikael returned to life, Rebekah was there to talk with him. He said that his intent was never to kill her, only Klaus as revenge for killing her mother. Rebekah told him that she knew what Klaus had done, but blamed Mikael for making Klaus this way, saying that it was not Klaus who destroyed their family, but Mikael when he turned them into vampires. 

Mikael meets with Klaus for the first time in 1000 years. Later, Mikael showed Damon the White Oak Stake, the only weapon that could permanently kill an Original. Damon asked him why he feeds on vampires. His reply was:"I had a hand in creating vampires but the blood lust was never my intention. Over the centuries, I've learned to feed from the predator, not the innocent."

Mikael kills Elena in front of Klaus. When Stefan came in, he fed on him and went with Damon to the Lockwood Mansion to proceed with the plan. At the mansion, Mikael found himself surrounded by hybrids. Klaus says that his hybrids will kill Mikael. Mikael replied that they cannot kill him, to which Klaus says "But it will make a hell of a party game". When Klaus came to the door, he tried to get Klaus to come out of the house to fight him, to no avail. Mikael dies.
Mikael bursting into flames after getting staked with the White Oak Stake.