The concept is an ability that can put counters on a permanent, such as lore counters. Something to track value without allowing the card to gain any initial value in ability. I've thought of experience counters but that is for players only. So far I've been using lore counters but this feels wrong since wizards has made them the default for sagas. That said lore counters fits this roll best so far.
Examples of how the counter would be used,
Example 1
a. Whenever a Creature you control ETBs, put a lore counter on THIS CARD.
b. 2G,Tap: Create 0/0 token. Put X +1/+1 counters on it, where X is the number of lore counters on THIS CARD.
Example 2
a. Take control of target creature and put 3 lore counters on it. It gains, "At the beginning of your upkeep, remove a lore counter. Then if there are no lore counters on this creature , return it to its owners control."
Example 3
a. Whenever a creature delt damage by THIS CARD this turn dies, put a lore counter on THIS CARD.
b. 1W,Remove X lore counters: Exile target creature with converted mana cost equal to X.
a. Whenever a Creature you control ETBs, put a lore counter on THIS CARD.
b. 2G,Tap: Create 0/0 token. Put X +1/+1 counters on it, where X is the number of lore counters on THIS CARD.
Example 2
a. Take control of target creature and put 3 lore counters on it. It gains, "At the beginning of your upkeep, remove a lore counter. Then if there are no lore counters on this creature , return it to its owners control."
Example 3
a. Whenever a creature delt damage by THIS CARD this turn dies, put a lore counter on THIS CARD.
b. 1W,Remove X lore counters: Exile target creature with converted mana cost equal to X.