Allister the Talking Helmet

This fantastical helm is imbued with the soul of a renown jousting knight. When he passed on, he had a dark wizard trap his soul in his jousting helmet so that he could instruct future generations. It conforms to the head of the wearer, but always fully covers the head, save for a small slit to see out from.

Allister is capable of giving instructions on the finer points of jousting, dueling, and general combat.

This helm gives a +1 AC as well as Expertise in Lances and you learn a lunging form that allows all melee weapons to count as having the Reach property.

While Mounted with a Lance, you can choose to extend your reach even further by sacrificing some balance and opening yourself up to an attack.
Before making an attack you can designate it as an Extension attack. Extension attacks can come in three different tiers: Extension 1, Extension 2, and Extension 3. For each tier, you can gain +5ft reach, but suffer -3 on the attack roll and -1AC until the start of your next turn. At Extension 3, you would gain +15 reach, but have a -6 on the Attack Roll and -3AC until the start of your next turn.

Also, once per Short Rest, you can ask for his help during combat to gain Advantage on one Attack.

Allister also makes for an excellent companion for dinner parties as he is versed in formal knightly etiquette and can give pointers on how to be proper. 

Notes: Expertise: Lance, Bonus: Armor Class, You must place this helm upon thine head under the light of the stars to gain its power, Combat, Headwear