Arcbound Hybrid

Most modular creatures bide a turn before they do anything; this one swings the moment it lands. The body enters as a 2/2 (modular is a replacement effect, so it never spends a frame as a 0/0 waiting on a trigger), and haste turns those two +1/+1 counters from inert future value into immediate pressure: it attacks the turn it arrives, then hands the counters to another artifact creature when it eventually trades or chump-blocks. That single keyword reorients the whole package. Modular's payoff is normally back-loaded, a death trigger you collect later; pairing it with haste front-loads the same value, so you get the body on offense first and the counter migration second. The four mana never sits idle. It reads as the aggressive counterpoint to the rest of the modular suite, where counters get hoarded for a single overloaded payoff in the Arcbound Ravager mold. Hybrid instead spends and recycles: attack, die into a fresh artifact creature, keep the counters in play. The cost is the obvious tax. Four mana for what is functionally a 2/2 with delayed upside is a steep ask outside a shell built entirely around artifact creatures and counter recursion, which is the only place the math closes. Read as a piece of the modular package rather than a standalone creature, the haste clause is the design tell: it is the modular card built to be on the battlefield now, not the one biding its time.