Thunderbird Tuft (Major)

This carved chunk of amber contains a single tuft of gray feathers, which spark with electricity to create an odd jittery sensation in anyone holding the amber for long. When used as part of a Thunderstrike spell, thunderbird tuft funnels electricity back into the spellcaster in a defensive nimbus. For 1 minute, any creature that touches you or that hits you with a melee unarmed attack or non-reach melee weapon attack takes 3d4 electricity damage, or 3d6 electricity damage if the creature is using a metal weapon.