When it attacks, look at the power of each creature you control. If the power is greater than its base power, you put +1/+1 counters on it based on the difference between those numbers. So if you have a Walking Ballista with 1 counter it’ll put an additional +1/+1 counter (since Ballista has base p/t of 0/0) If you Giant Growth that Ballista before combat it’ll be a 4/4 and you’ll put 4 counters in it instead.
![[LCI] Sovereign Okinec Ahau](https://mtgzone.com/pictrs/image/35c1f23b-9e4f-495d-bfe2-2bb4100badbe.webp){kind=link}
When it attacks, look at the power of each creature you control. If the power is greater than its base power, you put +1/+1 counters on it based on the difference between those numbers. So if you have a Walking Ballista with 1 counter it’ll put an additional +1/+1 counter (since Ballista has base p/t of 0/0) If you Giant Growth that Ballista before combat it’ll be a 4/4 and you’ll put 4 counters in it instead.