I don't know about everyone else, but when I first read about this card, I thought to myself "Cool, an E-Hero counterpart of Total Defense Shogun," but this monster does a little bit more than TDS. As a 1000 direct attacker OR a 2000 regular beatstick this monster can pack quite a punch if used correctly.
Well, you could use it as a chipper to your opponent's health with a little more damage than Inaba, or it could be used as a kind of wall against attacks with 2500 defense, the highest defensive Hero out in America so far (not until Mudballman comes out, anyway).
Strategies and game play:
One way to play Rampart Blaster would be to fusion summon it in defense mode while your opponent has a bunch of beatsticks out like GAF or even a Jinzo out, and while 1000 damage isn't much, it's better than getting your butt kicked by a whole flood of beatsticks or getting stopped by Level Limit Area B.
Out of all the E-Hero fusions, this one is most likely to stay on the field longest. Dealing only 1000 damage, it's not likely to get on the opponent's nerve unless it's late in the game. It would still be smart to only count on having Rampart Blaster on the field for a maximum of 3 turns, but if you run a deck that only focuses on one or two Hero fusions, Rampart Blaster would be best suited in a stall deck with Level Limit.
Combos with other cards:
As stated before, a good combo would be Level Limit - Area B. This keeps all monsters level 4 and above in defense mode, and since Rampart Blaster is a level 6 fusion it would be the only high-level monster who can attack, and attack directly. Also, you could boost Rampart Blasters attack with cards like Command Knight, The A. Forces, Gaia Power (although it loses some defensive edge, it wouldn't be worth the extra 250 damage), and Axe of Despair.
Also, and afterthought...Another good combo COULD be Reverse Trap: instead of losing half the attack strength, you'd gain what you would've lost, making the base damage 3000. I honestly don't know if that'll work, it's just something I thought up just now.
Ways to counteract it:
Basic monster destroyers/Poly negaters. Another way to destroy it (besides overpowering the defense with a boosted attack or BEWD) would be with the ever-popular Ninja Grandmaster Sasuke and/or Drilloid. Since both these cards are seeing a lot of play time now, Rampart Blaster may not last on the field as long as I said. Also, Sakuretsu Armor still works against Rampart Blaster.
Being able to inflict direct damage while in defense mode at 2500def is a definate strength.
Other than the lack of recursion with every E-Hero fusion, the fact that the direct damage is still an attack and not effect damage still makes it prone to cards like Sakuretsu Armor, Magic Cylinder, and Book of Moon.
Ultra and Ultimate rare in EEN.
Artwork and aesthetics:
Heavily armored gunner with a shield and massive gun against a combat-ridden background...looks pretty cool to me.
In an E-Hero deck and/or stall deck, I give it a 7.5/10.
In any other deck...it really doesn't belong.