Here are 25 important characters from the Ramayana with one-sentence descriptions for each:

1. Rama – The virtuous prince of Ayodhya, considered the seventh incarnation of Lord Vishnu, who embarks on a quest to rescue his wife, Sita.
2. Sita – The devoted wife of Rama, known for her purity and loyalty, who is abducted by Ravana.
3. Lakshmana – Rama’s loyal brother, who accompanies him during his exile and protects him with great courage.
4. Bharata – Rama's younger brother, who rules Ayodhya as a caretaker in his brother’s absence, refusing to sit on the throne.
5. Shatrughna – The youngest brother of Rama, who is devoted to Bharata and assists in maintaining the kingdom.
6. Ravana – The powerful demon king of Lanka, who kidnaps Sita, triggering the great battle with Rama.
7. Hanuman – The devoted monkey god and ardent follower of Rama, known for his immense strength and loyalty.
8. Sugriva – The king of the Vanaras (monkey tribe) who helps Rama in his quest to rescue Sita.
9. Vibhishana – Ravana's righteous brother, who joins Rama’s side after being mistreated by Ravana for advising him to return Sita.
10. Dasharatha – The king of Ayodhya and father of Rama, whose decision to exile Rama is driven by his promise to his wife Kaikeyi.
11. Kaikeyi – The queen of Ayodhya and mother of Bharata, who asks for Rama’s exile to fulfill a boon granted by Dasharatha.
12. Kausalya – The chief queen of Dasharatha and mother of Rama, known for her sorrow over her son’s exile.
13. Sumitra – The second queen of Dasharatha and mother of Lakshmana and Shatrughna, who supports Rama’s exile with grace.
14. Jatayu – The vulture king who attempts to rescue Sita from Ravana but is mortally wounded in the process.
15. Indrajit (Meghanada) – Ravana’s son, a formidable warrior who defeats even the gods but is ultimately slain by Lakshmana.
16. Kumbhakarna – Ravana’s giant brother, known for his immense appetite and strength, who is reluctantly drawn into the battle.
17. Shabari – A humble devotee of Rama who offers him berries during his exile, symbolizing selfless devotion.
18. Surpanakha – Ravana’s sister whose desire for Rama and subsequent humiliation by Lakshmana leads to the war between Rama and Ravana.
19. Angada – The son of Vali and a warrior in Sugriva’s army who plays a crucial role in Rama’s war against Ravana.
20. Vali – The mighty Vanara king and brother of Sugriva, who is killed by Rama in his quest for justice.
21. Tara – The wise and devoted wife of Vali, who later advises her son Angada and plays a key role in the Vanara kingdom.
22. Mandodari – Ravana’s pious and intelligent wife, who tries in vain to dissuade Ravana from his destructive path.
23. Ahiravan – The ruler of the netherworld and an ally of Ravana, who kidnaps Rama and Lakshmana but is defeated by Hanuman.
24. Trijata – A wise demoness and Ravana’s niece, who consoles and protects Sita during her captivity in Lanka.
25. Mareecha – Ravana’s uncle, who transforms into a golden deer to lure Rama away, aiding in Sita’s abduction.

These characters form the essence of the epic, each contributing to the storyline’s depth and moral lessons.

Here are descriptions of 25 more characters from the Ramayana:

1. Sumali – Ravana’s grandfather, who instigates him to gain power and conquer the world.
2. Mandavi – Bharata's wife and the daughter of King Janaka's brother, known for her supportive nature.
3. Urmila – Lakshmana's wife, who sacrifices her marital life during Rama’s exile, symbolizing patience and devotion.
4. Shrutakirti – Shatrughna’s wife and another cousin of Sita, known for her gentle and loving nature.
5. Nala – A skilled Vanara engineer, who helps build the bridge (Rama Setu) to Lanka.
6. Nila – Another chief of the Vanaras and a key figure in the construction of the bridge to Lanka.
7. Sampati – The elder brother of Jatayu, who helps Hanuman and the Vanaras locate Sita in Lanka.
8. Vasishtha – The royal sage and priest of the Raghu dynasty, who provides spiritual guidance to Rama and his family.
9. Agastya – A revered sage who gifts Rama a powerful bow and arrows, aiding him in the battle against Ravana.
10. Lava – The son of Rama and Sita, born during Sita's exile, who later plays a role in the retelling of the Ramayana.
11. Kusha – The twin brother of Lava, who also contributes to the retelling of the Ramayana alongside his brother.
12. Viradha – A demon who attacks Rama and Sita during their exile but is defeated by Rama.
13. Kara – A commander of Ravana’s army, who leads a failed attack on Rama in the forest.
14. Dushana – A demon general and an ally of Ravana, who fights alongside Kara but is also slain by Rama.
15. Akampana – A demon who advises Ravana to kidnap Sita after being defeated by Rama in battle.
16. Malyavan – An elder statesman and Ravana’s maternal grandfather, who advises Ravana to return Sita and avoid war.
17. Subahu – A demon who, along with Mareecha, disrupts the sacrificial rituals of sages until being killed by Rama.
18. Atikaya – A son of Ravana, known for his valor in battle, who is eventually killed by Lakshmana.
19. Shanta – The adopted daughter of King Dasharatha and Kausalya, who plays a lesser-known role in the epic as a devoted wife to sage Rishyashringa.
20. Dundubi – A buffalo demon who was killed by Vali in a mighty battle, showing Vali’s great strength.
21. Anasuya – The wife of sage Atri, who blesses Sita with the ability to endure hardships during her exile.
22. Tataka – A demoness and mother of Mareecha, who terrorizes the forest before being killed by Rama in his youth.
23. Kabandha – A demon cursed with a monstrous form, who is slain by Rama and Lakshmana, later providing them with guidance to Sugriva.
24. Shatananda – The chief priest of Mithila and the son of sage Gautama, who narrates Rama’s greatness to King Janaka.
25. Pratapbhanu – A former king mentioned in some retellings of the Ramayana, who was cursed and reborn as Ravana due to past misdeeds.

These characters, though sometimes less prominent, enrich the tapestry of the Ramayana with their varied roles and contributions to the epic's narrative.