Yeah I had a Poblem to get the whole Effect into some little sentences, because I'm mostly using the planpkan Image builder. (only for quantum marks in abilities I use gimp)
But your descriptions has also a flaw, or maybe mine,too. The charges will be rested after use, because it would be op. After 5 rounds you have a card taht does 5 damage to a creature. Next round it then does 6. When it will not be reseted.
What about:
Every Round this card gets a charge. Use the Ability to do damage equal to the charges. The charges then get reseted.