Mandroid Squadron

A 0/4 for two that gains you two life on arrival looks like defensive filler, and in a deck that casts it once it is exactly that: a body that walls off an early attacker while blunting the life race by a couple of points. The reason to think harder about it is the marriage of zero power to an enters trigger. A creature with no power adds nothing to combat and can be sacrificed, blinked, or bounced without costing you a beater, so the 2 life stops being incidental and becomes a repeatable payout. Flicker packages, recursion loops, and aristocrat shells all read the "when this enters" line as the whole point of the card, cycling the same wall through the battlefield for a steady drip of life. The tribal and type footing widens where it can live: Human and Soldier give it a home in go-wide token strategies, and the artifact type feeds any deck counting metalcraft, affinity, or artifact-matters payoffs for reasons of their own. The block is the floor. The ceiling is a deck that has turned "put this creature onto the battlefield" into an action it can take over and over, at which point a two-mana wall becomes an incremental life engine that also happens to hold the ground.