Elemental bender

When you gain this feat, you gain the following benefits:

• Using concentration and an action you can create spell charges equivalent to elemental spell slots of a certain damage type from sources of elemental power. The source of these charges is drained in the process but can be refilled with fuel or ingredients. Charges appear as orbs of elemental power that hover power around the user’s body or can be hidden within inventory compartments. Charges dissipate upon long rest or when concentration is broken. You can hold a number of charges equal to (spell casting modifier+proficiency bonus). Monks can absorb charges to regain lost ki points.
• tiny sized source (torch[fire], vial of acid[acid], water skin[cold/lighting], the sound of someone’s voice[thunder])- bonus action cantrip charge/1 ki point
• Small sized source (campfire[fire], bucket of acid[acid], pitcher of water[cold/lighting], the crash of something falling[thunder])- 1 lvl spell slot charge/2 ki points
• medium sized source (brazier[fire], vat of acid[acid], puddle of water[cold/lighting], sound of an explosion[thunder])- 2 lvl spell slot charge/3 ki points
• large sized source (bonfire of 10 ft or more[fire], pool of acid of 10ft or more[acid], pond of 10ft or more[lighting/cold], any sound which may shake the earth[thunder]) 3 lvl spell slot charge/4 ki points. 
• Any source larger than 10 ft can be considered higher lvl spell slot charge or worth more ki points at the Game Master’s discretion
• You may also use a reaction to consider an enemy attack of your damage type to be a source of power and reduce the elemental damage taken by all creatures within a 20-foot-radius of yourself by 1d10+(spell casting modifier) and ether use it to create charges or immediately cast a bolt of elemental energy within 30ft that deals all absorbed damage. 
• You can also infuse melee attacks with your elemental charges, dealing 1d6+(1d6 per lvl of charge used) of your elemental damage.