There are a few problems with this...

To begin with, you probably think Mr. Mime + Defender
= invulnerability...just like a million other people.
I will take a minute to prove this false using the
rulebook:

(under "Expert Rules - How do you figure out the
Damage?")

a.  Start w/ base damage (including applying effects
that cause the mathematical symbols next to the
number, like coin-flipping for NidoranF's Fury Swipes)
b.  Apply effects from previous attacks by the
attacking Pokemon (i. e. Swords Dance).  If damage is
now zero, quit.
c.  Check Weakness.
d.  Check Resistance.
e.  Figure out trainers on the attacker.
f.  Figure out trainers on the defender.
g.  Apply effects from previous attacks by the
defender (i.e. Grimer's Minimize) or relevant Pokemon
powers (i.e. Mr. Mime's Invisible Wall)
h.  Deal the damage
i.  Apply all other effects

So, let's say Defendered Mr. Mime gets Special
Punched...here's the damage figuring process...

a.  40
b.  (none) 40
c.  (not weak) 40
d.  (not resistant) 40
e.  (we'll assume no) 40
f.  (Defender!) 20
g.  (THEN Invisible Wall!) 20
h.  Deal 20 damage
i.  Do nothing

Since "special energy" isn't listed, if you look at
the process, the closest thing to it is "Trainer cards
attached to the defending pokemon".  So, that would be
the most logical place to put it until we get an
English Neo Rulebook.  So, treat the Steel Energy as a
lone defender, and you'll see why it's not practical.

The second problem:  Although Electrode is worded so
that you could pick Steel Energy, it doesn't have the
Steel Energy card bonus.  It's simply a double energy
card that makes energy you can use for steel attacks.
While this will be awesome to get a steel pokemon
running, it's worthless for a Mr. Mime.

Problem no. 3:  Not really with the combo itself, but
NGR does NOT retrieve Steel Energy.  It says "BASIC
energy" cards.  As of yet, the only cards that
retrieve non-basic energy that I know of are Fossil
Gastly and Recycle.  Personally, I think it would be
best to use Ecolo Gym from Neo, that is if this combo
worked.

Xhad Miller - (cmiller@ossm.edu, ishmael_42@yahoo.com)