Tyatle the Spiraling

Whenever you cast a spell from your hand with converted mana cost lesser than or equal to
Tyatle's power, it gains cascade. If you cast a spell
with converted mana cost higher than Tyatle's
power, put a +1/+1 counter on Tyatle.
"When I talked to him yesterday he seemed so kind.
But when I talked to him today he summoned
lightning from the sky and burned my house down.
I'm over it at this point."