Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on this creature.
At the beginning of your upkeep, you may move any number of +1/+1 counters from this creature onto other creatures.

Level Up

Enchant creature
When this Aura enters, put a +1/+1 counter on enchanted creature.
Enchanted creature has "Whenever this creature attacks, double the number of +1/+1 counters on it. Then if it has power 10 or greater, draw a card."

Forest

Setessan Champion

Constellation — Whenever an enchantment you control enters, put a +1/+1 counter on this creature and draw a card.

Thrun, Breaker of Silence

This spell can't be countered.
Trample
Thrun can't be the target of nongreen spells your opponents control or abilities from nongreen sources your opponents control.
During your turn, Thrun has indestructible.