“Yes, she has, but I chose to stay because I'm worried about my sister. Besides...Lady Ishtar has no need for me any more.”
Reinhardt (ラインハルト Rainharuto, alternatively translated Rinehart), is a boss character in Fire Emblem: Thracia 776. Said to be the second coming of the Crusader Tordo, he is the commander of the Gelben Ritter in the Freege army and Ishtar's personal guard, having known her since childhood. He is Olwen's brother, and the Mage Knight Kempf is scornful of him and considers him his rival. He is often by Ishtar's side, but she sends him away after Prince Julius reveals his jealousy of him. He, along with Olwen, are the only characters capable of wielding the tome Dime Thunder. If Olwen talks to him in Chapter 22, he presents her with the Holy Sword, which was in turn given to him by Ishtar.
At the Great River of Thracia, he leads the Gelben Ritter into battle against the Liberation Army.
Fire - A
Thunder - A
Wind - A
Reinhardt is a formidable opponent. He has four powerful skills, a Dime Thunder tome, a Master Sword, five leadership stars, five movement stars, and high stats to boot. If you have been using Olwen and have had her use the Ambush + Dime Thunder combo, Reinhardt has that too, but he is much, much stronger thanks to his skills.
Reinhardt will not attack his sister Olwen, so first have her talk to Reinhardt for her to obtain the Holy Sword. After this, you should blast Reinhardt with some kind of stat condition (have the status inflicter be boosted by the Magic Up Staff or Pure Water) and finish him off.
If you cannot do that, you should boost Tina's magic with a Magic Up Staff and have her steal his Dime Thunder so you can finish him off with ranged attacks. If you cannot do that either, you should have Olwen defeat him with her new Holy Sword, or get Mareeta in range to attack him with Mareeta's Sword, since it has Awareness, and thus it will disable his skills.
Another strategy is using a character with no weapons or items to act as bait for Reinhardt. Reinhardt will capture them which will lower his stats allowing him to be killed easier. This however can cause risk of losing a unit if Reinhardt manages to escape.
“So this...is...the end...”
—Reinhardt`s death quote
—Reinhardt's quote after being released