Banamaðr, Weapon of the Gods (Exhalted)

This weapon is made of finely crafted mithral, with runes carved into it; there is no bowstring, but when an arrow is notched, a thread of lightning forms in place of where a bowstring would be. Banamadr was forged by a Dwarven blacksmith and worshipper of Moradin for her sworn sister, a paladin of Kord. As such, Banamdr is considered a vestige of of both Kord and Moradin, and its' wielders have been known to hear the voices of both gods speaking to them. 

Banamadr is a shapeshifting weapon, adapting to the form of the favored weapon of the current wielder. This iteration is a longbow. Banamadr is considered a +3  magical weapon in its' exhalted state. 

In its' Exhalted state, Banamadr has a maximum of fifteen charges. One charge can be expended to cast Thunderwave, three can be expended to cast Lightning Bolt, or six can be expended to cast Chain Lightning; additional charges can be used to cast the spell at a higher level (one additional charge per spell level). The weapon regains [roll]3d4+3[/roll] charges at dawn. The spell uses your spell save DC and spell attack bonus.

In addition, once exhalted, the wielder becomes immune to Thunder and Lightning damage.

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

Notes: Bonus: Magic, Immunity: Thunder, Immunity: Lightning, spellcaster, Ammunition, Heavy, Range, Two-Handed, Slow