Balls of Steel

Lt. Surge's Electrode is prickly for your opponent because it has a chance to retaliate 20dmg if it gets damaged.
It can also do up to 60dmg for 3 energies with Power Ball which is pretty nuts, but it's at least 30, which isn't awful if you flip all 3 Tails.

But here's where things get interesting - with a Vermilion City Gym active, it means Lt. Surge's Electrode would either do an additional 10 damage for free if Heads, or would trigger a chance to Shock Blast, every turn.
Since Electrode only

Lt. Surge's Electrode is prickly for your opponent because it has a chance to retaliate 20dmg if it gets damaged.
It can also do up to 60dmg for 3 energies with Power Ball which is pretty nuts, but it's at least 30, which isn't awful if you flip all 3 Tails.

But here's where things get interesting - with a Vermilion City Gym active, it means Lt. Surge's Electrode would either do an additional 10 damage for free if Heads, or would trigger a chance to Shock Blast, every turn.
Since Electrode only has 70hp, it's not super tanky, and will whittle down it's own HP potentially with Shock Blast, but since this is a lot of small damaging amounts, adding 1 Special Metal Energy would mitigate a TON of it:

• It would take 0 damage on a Tails from Vermilion City Gym, and on a Heads, VCG would cancel out the -10 outgoing damage reduction from a non-Steel Pokemon attacking with a Metal Energy attached.
• It would take 0 damage from a Tails Shock Blast since it's both reducing outgoing and reducing incoming damage, but would still deal 10 damage to the opponent's Defending Pokemon
• It would be naturally more tanky by taking -10 damage from any usual attacks from your opponent's Pokemon by just having a Special Metal Energy on it, which also makes healing items like Gold Berry a lot more effective and predictable

Elekid is great to stall some opponent attacks with it's Baby Power, and is also great to Playful Punch when your active doesn't have enough energy on it or is Paralyzed. They can also evolve into Electabuzz which is a super high value basic.