Dreg Mangler

Haste
Scavenge {3}{B}{G} ({3}{B}{G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Abzan Advantage

Target player sacrifices an enchantment of their choice. Bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

Codespell Cleric

Vigilance
When Codespell Cleric enters, if it was the second spell you cast this turn, put a +1/+1 counter on target creature.

Iron Apprentice

Iron Apprentice enters with a +1/+1 counter on it.
When Iron Apprentice dies, if it had counters on it, put those counters on target creature you control.

Arcbound Worker

Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Arcbound Mouser

Lifelink
Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Chronicler of Heroes

When Chronicler of Heroes enters, draw a card if you control a creature with a +1/+1 counter on it.