Storvald, Frost Giant Jarl

The two modes hidden inside that enter-and-attack trigger are the whole design, and they point in opposite directions. Setting a creature to base 7/7 is the pump: it hardens your own beaters, turns a mana dork into a threat, or floods enough toughness onto something to survive a block. Setting a creature to base 1/1 is a removal-flavored control lever: it shrinks the opponent's biggest thing into a body that trades down, walks into your blockers, or dies to incidental damage. The word to fix on is base. The effect rewrites the target's printed power and toughness (or whatever earlier base-setting effect was already on it), but it does not touch the anthems and auras layered above it: a creature buffed by a static +X/+X still carries that bonus on top of the new 7/7 or 1/1. That layering quirk is what keeps the shrink mode honest, since a well-pumped attacker does not simply evaporate to the 1/1 clause. What holds the whole plan together is the ward shell wrapped around it. Ward 3 on the jarl and ward 3 handed to every other creature you control means the entire board demands a three-mana tax before anything can be pointed at, protecting the very engine you want firing turn after turn. That is the coherent piece: a green-white-blue giant that sizes creatures up and down at will, breaks combat symmetry with a single target, and taxes the removal that would answer any of it.