A golden ring with a small blue gemstone in the center. A hazy runic symbol can be seen in the center of the gemstone. 

Kaligar was a general during the great war of the southern marches. He was famous for his leadership ability and magical prowess. Those who wield Kaligars ring will have the power of Kaligar granted to them...on one condition. They must earn the powers through a series of tests. (It is up to the DM if they want to reveal the tests to the player wielding the ring.)

Upon first equipping the ring, the wielder has +1 to hit with ranged spell attacks.

Kaligar's trials are as follows, they must be completed in order (or not. This is up to the DM.) Once completed a new permanent power is added to Kaligar's Ring.

1.Kaligar's Trial of Power: Roll a natural 20 on a spell attack. At the exact moment that the trial is completed, instead of doubling the  damage for that spell,  normal damage is rolled, the ring and the wielder glow faintly blue casting dim light for 5 ft for 1 round, and the wielder unlocks the first new power for Kaligar's ring, "Kaligar's Precise Spellcasting"

Kaligar's Precise Spellcasting: The wielder now has a greater understand on how to more effectively use their spell attacks to deal maximum damage.

Whenever the wielder rolls a natural 20 on a spell attack, add 1d4 additional damage to the attack.

2. Kaligar's trial of Wit: This trial is granted by the DM when a player successfully completes a task creatively or in an unexpected way. For example, the player successfully solves or bypasses a puzzle in a creative way that wasn't the "correct" solution, or a player uses a non combat-oriented spell or ability creatively in combat to gain an advantage. Upon completing the trial the ring emits a flash of bright green light and the gem transforms into a diamond. Unlocks the power "Kaligar's Intuition"

Kaligar's Intuition: The wielder has showed the ability to make the best out of a bad situation.

Once per long rest, if they player rolls a natural 1 on an ability check, they may re-roll but must keep the second roll. 

3. Kaligar's Trial of Leadership: The wielder successfully persuades a creature to go against their natural instincts and to follow the wielder into danger's path for a cause. Will not work if the creature is under the effect of a spell.  Upon completing the trial, the ring emits a flash of bright multicolored light and the gemstone transforms into a small translucent orb with dancing lights in the center of it and light seems to refract strangely and randomly in the orb. Unlocks the power, "Kaligar's Word"

Kaligar's Word: The wielder has an uncanny ability to sway the opinions of others. Their words carry more weight than other's around them.

The wielder has advantage on Charisma (Persuasion) Checks.

*If the ring is removed, it transforms into it's original form.

Notes: Bonus: Ranged Spell Attacks, by anyone., Buff