don't stick too rigidly to the actual patterns that the game follows and try to follow the game's basic feeling
for instance his up-b could be building a floating brick platform that eventually falls away, and his side-bs could build large walls that deflect projectiles and reject movement
his A attacks could utilize extremely short-ranged projectile weapons (sort of like mega man) with the twist that you can't move most of them while firing, but they all do at least decent damage at close range and aren't necessarily the only things in his arsenal
for instance his normal A could be a fast-firing semi-automatic Gun attack, quickly racking up damage ala Falco's blaster but at much shorter range (less then maybe 3 player-widths away; essentially long melee range), then use your side-A to lash out and do damage to people caught in your barrage- i'm thinking a long swipe with a sword, like Link's side-smash but more like a poor limbless imitation
then your side-smash could be the Tier+Tactical combat shotgun- fire uncharged to do normal (but good) damage akin to Mario's side-smash and knockback and fire charged to do better damage (and knockback) closer to Snake's normal side-smash
actually what if some of blockhead's attacks were imitations based off of other character's moves, with his weapons?
