A-Nezumi Prowler

Ninjutsu has always been a delivery mechanism, and this design treats what gets delivered as more than a one-turn tempo swing. Most ninja swap in for a hit and leave nothing behind when they die; the counters this Rat hands out are permanent, so it reshapes the board even after it is gone. The enter trigger drops deathtouch and lifelink onto any creature you control, which makes the choice of recipient the whole decision. Keep them on the 3/1 to turn an evasive attacker into a life-gaining body that trades up against anything on defense, or graft them onto the beater you actually plan to protect, splitting the outlet off from the reward. Bounce an unblocked attacker to sneak the Prowler in during combat, then decide where the keywords live. Because the counters sit on the recipient rather than on the creature that granted them, they survive the Prowler's death, cooperate with anything that copies or moves counters, and convert a repeatable evasion engine into a way to seed a durable threat somewhere else. The catch is fragility: a 3/1 committed to an open board dies to almost anything, which is exactly why it prefers to enter tapped and attacking through ninjutsu rather than get cast into a waiting removal spell. It is a small piece of design that widens what ninjutsu is allowed to do, using the tempo trick as a courier for keyword counters.