Lumbering Battlement
The blink payoff turned inside out. Most white creatures that exile something on entry are answers to the opponent's board, or single-target protection that hands a threat back later. This one only touches creatures you control, so it never functions as removal: what it offers is shelter, and it charges you for the room. Every nontoken creature you tuck underneath stays gone until the Battlement leaves play, and that leaving is not a loss but a return: a bounce spell, an exile effect, or the opponent's own flicker all send your stashed board back at once, safe and simultaneous. Its body swells by two in each dimension for each card buried with it, so the more you protect, the fatter (and the more inviting a removal target) the whole package becomes. This is the trade the design is built to enforce. Bury three creatures and you get a hulking beast, but a single answer to the Battlement dumps all three back onto the battlefield at the same moment, re-firing every enter-the-battlefield trigger they carry. That last part is the reason it rewards re-entry engines rather than raw size: getting the creatures back is itself the payload, so it wants dorks and hatebears with triggers worth resolving twice, not fatties worth hiding. The frame invites the answer, and the answer hands you your board back with interest. A shelter that keeps making itself worth killing, and pays out when it is.
