Melira, Sylvok Outcast + River Kelpie + Yahenni, Undying Partisan

Melira, Sylvok Outcast

River Kelpie

Yahenni, Undying Partisan

How it works

1. Activate Yahenni by sacrificing River Kelpie.
2. When River Kelpie dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to Melira.
3. When River Kelpie enters, it triggers, causing you to draw a card
4. Resolve the Yahenni ability.
5. Repeat.