Mer-Ek Nightblade
Creature — Orc Assassin
Outlast (, 
: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has deathtouch.
Lucas Graciano
Iconic Masters (IMA)
• #97Rulings
Several creatures with outlast also grant an ability to creatures you control with +1/+1 counters on them, including themselves. These counters could come from an outlast ability, but any +1/+1 counter on the creature will count.
(wotc • 2014-09-20)
The cost to activate a creature’s outlast ability includes the tap symbol ({T}). A creature’s outlast ability can’t be activated unless that creature has been under your control continuously since the beginning of your turn.
(wotc • 2014-09-20)
Rulings
Several creatures with outlast also grant an ability to creatures you control with +1/+1 counters on them, including themselves. These counters could come from an outlast ability, but any +1/+1 counter on the creature will count.
(wotc • 2014-09-20)
The cost to activate a creature’s outlast ability includes the tap symbol ({T}). A creature’s outlast ability can’t be activated unless that creature has been under your control continuously since the beginning of your turn.
(wotc • 2014-09-20)