What did Alexander the Great look like?
According to various sources, Alexander III of Macedonia possessed all the basic character traits of an ambitious commander and a successful leader. Almost all historical sources agree on some basic attributes:
Alexander was very clever. Raised in the court of the influential Philip II of Macedon, he was well educated in his time, and between the ages of 13 and 16 he was personally tutored by the Athenian philosopher and scientific theorist Aristotle, and even gave Aristotle a personal manuscript of Homer's writings in the Iliad. In addition, throughout his upbringing he would receive the best military and classical education under the guidance of Leonidas of Epirus, Lisimachus of Arcanania, and the Macedonian generals Antipat and Palmenion (the latter of whom would become one of his most successful figures). The general conquered Persia), learning various skills such as horsemanship, military planning, playing the seven-stringed piano, and of course reading, which was his favorite pastime.
Alexander was very brave. He has a bizarre, almost masochistic desire to face almost improbable opportunities, and even if it means putting himself in danger, he will never shy away from challenges. Legend has it that Alexander tamed a powerful, aggressive, and wild stallion named Bucepharus at the age of 12, before whom several experienced riders were completely unable to tame it. Bucephalus would serve as Alexander's main mount until he was killed at the Battle of Hydaspes in 326 BC. This is just one example of the absolute bravery this man has had since he was young.
Alexander was very religious. The chronicle tells us that he would worship the gods, especially Ares, Apollo, and Zeus, around the time of each Armageddon, and held several religious festivals during the campaign, and even erected "pseudo-miracles" such as small temples and monuments near Armageddon. A battlefield dedicated to the gods. His piety and desire to maintain a good relationship with God was probably due to his belief that he was the son of Zeus, as his mother Olympias said. Every military operation he planned had to be filled with the blessings of the gods, though this belief in the intervention of the gods often led some of his less superstitious accomplices astray.
Alexander was a talented and skilled military commander. It seems obvious that a man does not receive the honorific title of "great" for no reason; he has never lost a battle in his life. His ability to overcome the most impressive and unlikely victory over the Achaemenid dynasty and its extremely superior numerical and logistical resources is beyond reproach. The Siege of Pelim and the Battles of Granicus, Issus, Tyre, Gaugamela, and Hildaspes depict a commander with keen insight into how to read the battlefield and a deep understanding of how to use his power economically. During his lifetime, his conquests enabled him to hold a number of different titles, including Basiles of Macedonia, overlord of the Greek Confederation, pharaoh of Egypt, king of Asia, and most importantly, Shahansha of Persia ("King of Kings").
Alexander is absolutely full of charm and wisdom. It is worth noting that Alexander was very confident from an early age, even jealous of his father, cautiously disgusted by Philip's success, for he feared that he would have nothing to conquer when he grew up. Nevertheless, as his life went on, prophecies from the oracles of Delphi and Siva, and his severance of the famous Gordian knot, supported Alexander's belief that he would rule the entire known world. His charisma and outgoingness are legendary, and because of this his soldiers remain loyal to him. He was able to make friends with cautious opponents as long as they recognized his supremacy and rewarded those who were loyal to him very generously. Unsurprisingly, during the battle, wounded and dying Macedonian soldiers were often heard chanting "Praise Alexander!" Hail Strategy! It is even said that in the Battle of Sogdian Rock, Alexander persuaded the entire Bactrian and Sogdian garrisons to surrender by ordering hundreds of unarmed hypastpistai to climb the cliffs outside the fortress at night, and more than 40,000 soldiers in the nominal fortress surrendered. The huge Persian army saw this small force on the top of the cliff, and was stunned by Alexander's understanding, and fell without a fight.
Still, in all his details, no one is perfect, and so is Alexander. Some of his more obnoxious attributes have also been documented, despite varying degrees of academic skepticism.
Alexander was grumpy and fond of narcissism. After forcing the Oracle of Delphi to give him a prophecy in the off-season, Alexander is said to interpret her half-hearted prophecy as his descendant of God and Immortal. Whether this was simple anti-Alexander propaganda or not, it was well known that he had lived his life believing that he would never lose his life in battle. While it may enhance his legendary charm, for intrinsic reasons it means that Alexander sometimes needs god-like treatment, almost always has to act his own way, and if someone rolls his eyeballs at him, he lashs out at someone.
Like his father, Alexander was notorious for sexual promiscuity. Even today, his record with numerous women, including the wife of his closest general, is widely known, especially considering that he did not cease his infidelity even after his marriage to Roxana of Bactria. Of course, his unfortunate status as a "slave" meant that his sexuality also included many men, especially he was Alexander's closest friend and most trusted general, Heffistian. While there is no contemporary Hellenistic source to confirm Alexander's bisexuality and potentially homosexual relationship, several Roman and Greco-Roman historians such as Quintus Curtius Rufus, Arrian, Diodorus Siculus, and Plutarch have speculated centuries later, some of whom claimed access to private correspondence shared by the two men.
Alexander hated politics. This is not to say that Alexander was necessarily politically incompetent. In fact, he was actually an accomplished and talented politician who calmed the unrest in Macedonia and Greece and improved the political infrastructure before crossing to Asia. Nevertheless, Alexander has always seen domestic governance as a tool for maintaining the army and has never planned ahead of time for the establishment of long-term governance institutions during and/or after his conquests. This would lead to the disintegration of his newly conquered empire after his untimely death in 323 BC, as his kingdom lacked the necessary central administration to survive the succession crisis, leading his generals and vassals, namely successors, to divide his empire between them.
Alexander was probably afraid of cats. Some say that despite Alexander's bravery, he may suffer from phobias, or fear of cats. However, there is little historical record on this topic, so it may just be a guess. After all, other historical strongmen who are said to be afraid of the feline biological family include Julius Caesar, Genghis Khan, Napoleon Bonaparte, Benito Mussolini, and Adolf Hitler. In this vein of radical alpha males, it is perfectly reasonable that Alexander might be one of these historical figures, but we have little academic insight or historical record to suggest this.
Surprisingly, although he is one of the most well-known figures in the Greek world, much of our knowledge of Alexander was not really written until Roman times, most reliably through the Greek historian Arian in his Alexander the Great and Sicily Theodoros in his multi-volume historical bibliography. There is also a wealth of second-hand sources that can provide a reasonable evaluation of historical evidence. My advice to you is to read Jacob Abbott's Alexander the Great, as he offers crash courses on Alexander's life, merits, and personality without delving into details or exploring more abstract concepts. This is certainly useful for beginners on the subject.
Think of this explanation as a brief overview of the entire available knowledge base.