Damnation

Destroy all creatures. They can't be regenerated.

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Parallel Lives

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Emerald Medallion

Green spells you cast cost {1} less to cast.

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.