The Oozing Temple (3rd level)

2nd-level transmutation
Casting Time: 1 bonus action
Range: Touch
Components: V, S
Duration: Concentration, up to 1 hour
You touch a nonmagical weapon. Until the spell ends, that weapon becomes a magic weapon with a +1 bonus to attack rolls and damage rolls.

When you choose this tradition at 2nd level, you learn to infuse creatures with residual transmutation magic to retaliate attacks.

Whenever you expend a spell slot to cast a transmutation spell of 1st level or higher, you can choose an ally you can see within 60 feet of you. The ally gains a number of transfusion charges equal to the level of the spell you cast. An ally can hold a number of your transfusion charges up to your Intelligence modifier (minimum of 1).

When an ally bearing any of your transfusion charges takes damage, you can use your reaction to detonate all of your transfusion charges it has. Each creature within 5 feet of the ally (other than the ally and any other allies bearing your transfusion charges) must succeed on a Dexterity saving throw against your spell save DC or take 1d6 force damage per charge detonated.

A transfusion charge is lost once detonated and any undetonated transfusion charges are lost when you finish a long rest.