Sun-Dappled Celebrant

Convoke and vigilance make an odd pair, and that friction is the design argument here. Convoke wants a flooded board of small creatures to cash in for a discount, effectively deploying a 5/6 for a fraction of six mana on a turn you already have a wide battlefield. But tapping your team to pay for a creature normally strips your attack: the bodies that funded the discount are tapped out, and the fresh arrival, like any convoked topper, has no haste and sits back a turn before it can swing. Vigilance is what pays that tempo tax forward. Once this untaps and joins the assault, it never has to choose between defending the board you convoked with and pressing the attack, so the wall you built to cheat it in becomes the wall it holds down while everything else runs at the opponent. That is the loop the Treefolk-Cleric line points at: a go-wide white shell where the token count that buys the convoke discount is the same count that survives an alpha strike and keeps the door shut behind it. The card scales precisely with the thing that makes it cheap, which is a clean reward in an aggressive white board state and close to dead weight in a deck that never develops one.