Deepfathom Echo (ES) Nightmare put three +1/+1 counters on

put three +1/+1 counters on it for each Dragon card you reveal in your hand

Counter target instant or sorcery spell unless its controller pays {1}

(It deals damage to creatures in the form of -1/-1 counters

Sacrifice a nontoken artifact: Create a 1/1 blue Thopter artifact creature token with flying

Deepfathom Echo (ES) Nightmare put three +1/+1 counters onAt the beginning of combat on your turn, Deepfathom Echo explores. Then you may have it become a copy of another creature you control until end of turn. (To have this creature explore, reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1 +1 counter on this creature, then put the card back or put it into your graveyard.)