Arcane Bow

At first, it just seems like a Longbow +2 with an intricate pattern in it. After attuning with him he reveals its true power. the arrow damage becomes force damage. His intricate pattern lights up, revealing  1d6+2 mystic runes.  When attuned,  the Item gains charges equal to the quantity of runes, each one of a different magic school,  each one having different abilities, and each one has 1 charge. Use table 1 to determine with is the rune in the bow. You can use a charge to imbue the string of the arrow with the magic school energy of one of the runes. While thiis happens  you're concidered to have concentration, like in a spell.When this happens, the light of the rune goes out and athe string of the arrow becomes the same color. The arrow gains the following effects for one minute, or you can dismiss it as a bonus action, equal to the type of  charge you chose:

>General effects:

-If you use any arcane shot option that has a different magic school from the energy imbued in the string, the energis negate themselves, wasting your arcane shot and ending the effect.

-The arrow gains the damage type equal to it's arcane shot equivalent.

D8:

1>Abjuration Rune:

 When you shot an arrrow imbued with the Banishing arrow arcane shot, the arrow starts to appear to be shifty, like it swaping between planes of existence. The time period lasts for 3 round, finishing in the end of his third turn banned. He also takes 1D6 extra of force damage.

2>Conjuration Rune: 

When you shot an arrrow imbued with the Grasping arrow arcane shot, the arrow liberrates a poisonous gas. Creatures 5 feet around the target must make a constitution saving trow (DC equal to your arcane shot DC) or will will take 2d6 of poison damage, it's movements will be reduced in 5 feet and will take 1D6 fo poison damage when it moves at least 1 foot for 2 rounds, and takes half of the damage with a success and it isn't affected by the effect.

3>Divination Rune:

When you shot an arrrow imbued with the Seeking arrow arcane shot, a ethereal like chain appears in the front of the arrow, like it's being dragged by it. The arrow the target will be under the effects of Mind Spike spell, not including the damage, for one minute and will receive the normal damage of the arcane arrow, and will just suffer half of the damage on a succesfull save. The distance that the arrow can travel also doubles.

4>Enchantment Rune:

When you shot an arrow imbued with the Beguiling arrow arcane shot, the point of the arrow becomes a pink heart. The charmed effect lasts for 3 rounds, ending at the end of the third round that he's charmed. The target also takes 1D6 extra of psychic damage.

5>  Evocation Rune:

When you shot an arrow imbued with the  Bursting arrow arcane shot, the arrow gets on fire when it goes out of the bow. The area of the effect of the arrow increases by 5 feet, and the exploxion gives 1d6 extra of fire damage.

6>Illusion Rune:

When you shot an arrow imbued with the Shadow arrow arcane shot, the arrow becomes colorful with really dark collors. The creatute hit by the arrow must make a constitution save throw, becoming blinded for 1round and receiving thee full damage of the arcane arrow in a failed save and just suffering half of the damage in a succesfull save. The creature also takes 1D6 extra of psychic damage.

7>Necromancy Rune:

When you shoot an arrow imbued with the  Enfeenbling arrow arcane shot, the arrow adquires a rooten aspect, like in any moment it would crumble to dust. On a failed save, the creature takes full damage of the arcane arrow shot and is affected by one random effect of the Contagion spell, and just receiving half of the damage on a failed save. The arrow also crumbles to dust after this.

8>Transmutation Rune: 

When you shot an arrow imbued with the Piercing arrow  arcane shot, the arrow emmanates a brown aura and creates a ethereal line between the place it was shot and where it lands. If someone moves through this line, in the line and/or uses an action in the line, you can use your reaction to make the arrow go back to the beggining point, aplicating the effects like it was shot with the Piercing arrow arcane shot option (DC 15). This effect ends after one minute or after it´s used.

After the effect ends, if you use another charge in a one hour period, roll a D20. If the result is 1, the bow crumbles to dust. One random rune recovers all of it's charges on the dawn. 

Proficiency with a Longbow allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: arcane archer (requires 3 hours of attunement for 3 days), Ammunition, Heavy, Range, Two-Handed, Slow