Interesting and very annoying. Wouldn't take much for me to want 4 of these, especially with any piece of equipment.

Its a variation on Seasoned Marshal that is a 1/3 for that can tap anything rather than just creatures. The Marshall cost and was Uncommon so this is seriously undercosted. Don't get me wrong I like the idea, but it needs to cost more. If its staying common it would probably need to cost a lot more, making it unplayable; otherwise it would seriously warp limited play. Imagine getting more than 1 of these in a draft, say you got 3 and had them all in play, your opponent would need to control at least 4 creatures to be able to block even one of these. ­ for this at uncommon isn't unreasonable. Or you could drop it to a 1/2 and maybe get away with at common.

What if it just went after lands (which was what I originally intended him for anyway)? He can only swing during your turn, which means he's really only inhibiting responsive plays after your declare attackers step. Anti-control control.

Why not just: Non-creature permanent? Allows for the tax effect, but also interactions (however few) with cards like Howling Mine. Toughness is rather high but since it only works as a sorcery, opponents will still be able to do things on their turn.

Land or artifact? Allowing the tapping of enchantments or planeswalkers is pointless and dumb. Equipment too, but there's really no way to prevent that.

Nah, land only. Cleaner.