Magmyth, a Myth No More

Magmyth, a Myth No More comes into play with seven myth counters on it. If it has zero or less myth counters on it, sacrifice it. You may play a Mountain when you sacrifice Magmyth, a Myth No More.
Whenever Magmyth, a Myth No More attacks or blocks, remove a myth counter from it.
{r}{r}{3}{t}:Deal 3 damage to target creature.
"Has noone heard of me? Well, that will soon change."