Hollowmurk Siege

As this enchantment enters, choose Sultai or Abzan.
• Sultai — Whenever a counter is put on a creature you control, draw a card. This ability triggers only once each turn.
• Abzan — Whenever you attack, put a +1/+1 counter on target attacking creature. It gains menace until end of turn.

Ajani Goldmane

+1: You gain 2 life.
−1: Put a +1/+1 counter on each creature you control. Those creatures gain vigilance until end of turn.
−6: Create a white Avatar creature token. It has "This token's power and toughness are each equal to your life total."

Abzan Ascendancy

When this enchantment enters, put a +1/+1 counter on each creature you control.
Whenever a nontoken creature you control dies, create a 1/1 white Spirit creature token with flying.