Storm Dealer

You were born as a healer, raised as a truth seeker, with the soul of a fighter. Your devotion and dedication to the Storm have been recognized and a new glimpsy spark spreads throughtout your body: now, you have finally figured out how to set the terms with the power of Lighting and Thunder.

You can activate this feat a number of time per day equal to your halved Proficiency Bonus.

When you deal Lightning/Thunder damages with an attack, you can use your Bonus Action to choose any number of allied creatures (including you) within 10 ft. that you can see. You can heal Hit Points equal to half the damage dealt with THAT attack (if that attack hit more than one target, the damage dealt is the sum of the damages dealt to the single targets with THAT attack), distributed as you like among the chosen creatures.

The maximum Hit Points you can heal every time you use with this effect is equal to double the sum of your Spellcasting Ability Modifier and your Spellcaster Level.

Max Healable HPs per activation = [ (SpellcastingAbilityModifier + SpellcasterLevel) * 2 ]

You can also choose allied creatures that are within 10 ft. from your Familiar (if you have one) that you or him/her can see.

E.g. 1: your 10 level Tempest Cleric (+5 on WISDOM) uses Thunder Step to teleport himself away from 2 enemies that were surrounding him to an unoccupied space within 10ft his allies. The first enemy gets 11 Thunder damages and the second gets 22. The Cleric then decides to activate Storm Dealer to heal his allies (in range and in sight). At his level, he can heal a maximum amount of HPs equal to [ (5+10) * 2] = 30 HPs; but in this case, he dealt a total of 11 + 22 = 33 Thunder damages, so he can distribute only 33/2 = 16 healable HPs.

E.g. 2: your 12 level Tempest Cleric (+5 on WISDOM) uses Chain Lightning hitting a first creature and then other 2 creature and an object within 30ft from the first target. The 3 creatures get respectively 33, 56 and 30 Lightning damages, while the object get 40 damages. The Cleric then decides to activate Storm Dealer to heal his allies (in range and in sight). At his level, he can heal a maximum amount of HPs equal to [ (5+12) * 2] = 34 HPs; in this case, he dealt a total of 33 + 56 + 30 = 119 Lightning damages (damages to objects are not considered, but if your DM does want to include them, then he's free to do it), so he got over the Max Healable HPs 119/2 = 59. In the end, he wasted 59 - 34 = 25 potential healable HPs.

In case you were wondering, yes I'm a Tempest Cleric. And yes, I find it difficult healing allies and attacking foes, so i needed a solution