Anastacius put a lot of black magic into Jeanette that, by sucking the life force out of everyone (Claude) he's able to come. Claude killed Ana when they were teens, Claude is king but Ana thinks thats his rightful seat. So yes, he Anastacius came back to one day kill Claude and take over the throne. You might be able to see this in snippets of "scenes" from "The Lovely Princess" where Claude was terminally ill and Anastacius came from the shadows and said leave him be.
Maybe more precisely after anastacius was killed by claude memory as he reincarnated as 'the greatest king' back again (I'm forgot his name, Anyway Lucas once mentioned his name in Season 1)
Ohh okay that makes sense thank you!
Anastacius is the crown prince, he is the rightful heir, while Claude are illegitimate child. At first he is a good brother, but his mother abuse, the black aura possessing him (forgot his name, Athy mention him the strongest Emperor in history while Lucas said he is the weakest) make him evil. Not to mention Claude magic power grew stronger make him insecure and envious, so he cheated with Claude fiancee, still Claude didn't retaliate, Claude has no desire for the throne, the only reason Claude kill Anastacius is because he is experimenting with black magic and put the empire and the people in jeopardy.
Ohh omg that makes more sense now i didn't really understood why claude killed anastacius but now i do, thank you!
yeah, I forgot in what chapter but it mention that the reason Claude kill Anastacius. For the people of the empire, Clause is a hero who drive out the dark era, he is ruthless to the noble but wise to the commoner.
actually claude killed anastacius because anastacius killed his mother. like you said he didn't particularly care about the throne. he just wanted revenge. the responsibilities for taking care of the empire came after he became the only royal legitimate to become emperor
"saving the empire from black magic" was just a pretense.
Wait did Anastacius came back after "dieing" because he wanted revenge on Claude or something..?