Need help with difficult problem solving card text

[I Hate Snatch Steal]

I have not finalized the effect of the card that's going to have the clause I'm having trouble with, so the effect described below is a simplistic use of the part I need help wording.

 

The part I'm having trouble with will be something like this:

 

You can [do something] by discarding X cards. X begins at 0 and increases by [value] each time [something happens]. X decreases by [value] each time [something happens]. X's value is shared by all copies of [card name here]

 

For example:

Name: Insert monster name here

Effect: You can special summon this card (from your graveyard) by discarding X cards. X begins at 0 and increases by 1 each time you special summon "Insert Monster Name Here" his way. Once per turn during your End Phase, X decreases by 2. X's value is shared by all copies of "Insert monster name here".

 

Can anyone think of a better wording for this? Also feel free to reply if you have questions about how these effects work.

 

edit: First revision:

You can special summon this card (from your graveyard) by discarding 1 card for each time you've special summoned "Insert monster name here" this way during this duel. Once per turn during your End Phase, decrease the number of discards needed to special summon "Insert monster name here" this way by 2.

[Dova]

You can Special Summon this card from your Graveyard by discarding a number of cards equal to the number of "Monster Name" you have Special Summoned this Duel. At the end of each of your turns, you are you treated as having Special Summoned "Monster Name" 2 less times during this Duel.

 

Discard a number of cards; Special Summon this card from your Graveyard. This cost is equal to the number of "Monster Name" you have Special Summoned this turn, and decreases by 2 during each of your End Phases.

 

That's two attempts.

[Astolfo]

I'm not entirely sure, this is quite unusual, but I'll try it.

 

 

 

You can Special Summon this card (from your Graveyard) by discarding 1 card for every time you have previously Special Summoned "name here" this way during this Duel. During each of your End Phases, you can discard 2 less cards for the next Special Summon of "insert card name here".