"It is the nature of souls that they burn more brightly together than apart."
—Vessifrus, flamekin demagogue

Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it.

Shared Animosity

The Lost Caverns of Ixalan Commander

"The feud between dwarves and redcaps had raged for so long that no one could quite recall how it started. Few would believe it was sparked by a long-ago dispute over a spoon."
—*Assault on Delverhaugh*

Wilds of Eldraine: Enchanting Tales

Out from the beleaguered hills, knights of Gondor, Riders of Rohan, and Dúnedain of the North drove against their wavering foes, piercing the press with the thrust of bitter spears.