Sigiled Contender

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 lifelink.

Boast — : Untap this creature. Put a +1/+1 counter on it. (Activate only if this creature attacked this turn and only once each turn.)

: Put a +1/+1 counter on this creature.

Whenever you gain life, put a +1/+1 counter on this creature.

As long as you have 25 or more life, this creature has double strike. (It deals both first-strike and regular combat damage.)

This creature has flying as long as it's enchanted.

Flying, lifelink

Heroic — Whenever you cast a spell that targets this creature, put a +1/+1 counter on this creature.