Tombo, Arix Spawn

Green instants and sorceries you cast cost {1} less for each Island you control.
Blue creature spells you cast cost {1} less for each Forest you control.
Whenever an Island enters the battlefield under your control, you may cast creature spells as though they had flash until your next turn.
Whenever a Forest enters the battlefield under your control, blue instants and sorceries you cast gain cascade until your next turn.