The Goo Strikes Bax

When Chien-Pao ex and Baxcalibur were unveiled, the first card that popped in my mind to use as a secondary attacker was Kyurem (EVS 116). For 2 water and 1 metal energy, Kyurem's Extreme Freeze attack deals 60 damage for each water energy you discard from your Pokémon. Sounds kinda familiar, huh? Essentially, Kyurem gives you Chien-Pao's attack and only gives up one prize (to Chien-Pao's two), but the trade-off is that the attack costs an additional metal energy  and, of course,

When Chien-Pao ex and Baxcalibur were unveiled, the first card that popped in my mind to use as a secondary attacker was Kyurem (EVS 116). For 2 water and 1 metal energy, Kyurem's Extreme Freeze attack deals 60 damage for each water energy you discard from your Pokémon. Sounds kinda familiar, huh? Essentially, Kyurem gives you Chien-Pao's attack and only gives up one prize (to Chien-Pao's two), but the trade-off is that the attack costs an additional metal energy  and, of course, Kyurem can't go fetch you two water energy from your deck. Despite the higher energy cost, Kyurem can still be powered up in a single turn thanks to Baxcalibur's Super Cold ability. Just accelerate two water using Super Cold and attach a Luminous Energy from hand. Hisuian Goodra VSTAR, with its Rolling Iron attack (cost = 1 water, 1 metal, 1 colorless) can be powered up in exactly the same way.

Ideally, you get a Chien-Pao ex in play early and use its Shivery Chill ability a couple times to snag water energy from deck (thinning it in the process). If you can avoid using Chien-Pao as an attacker, though, you're generally better off. Granted you draw into a Luminous Energy, Kyurem is usually the better choice when you need to take down a high HP Pokemon. If your opponent has unprotected low HP bench-sitters, turn to Radiant Greninja. Then, of course, you have Goodra to dish out 200 damage and soak up damage, which is reduced by 80 thanks to Rolling Iron. If you're opponent can't OHKO your Goodra, then they're potentially in for a tough match, because this deck plays Cheryl as a healing option in addition to Goodra's Moisture Star VSTAR ability. Cheryl may not seem ideal at first glance, considering it forces you to discard all energy attached to your evolution Pokemon, but with Superior Energy Retrieval, you can easily get water energy back into your hand and then attach it to Goodra again using Baxcalibur's Super Cold ability. Provided you have another Luminous Energy in hand, you won't miss a beat and can back to attacking right away.

The reason Luminous Energy is used in this deck instead of basic metal energy is because, in a pinch, it can be discarded with Chien-Pao's and Kyurem'a attack to increase damage (their attacks don't specify that the water energy must be basic and since Luminous Energy is simultaneously all types, it works). Since the Luminous Energy can't be recovered, you must be selective about discarding it, but when it makes the difference between getting a KO or not, it's nice to have the option. All that said, a strong case can be made for playing basic metal energy instead. Basic metal energy could be recovered using Superior Energy Retrieval, which is especially useful in the event you play Cheryl and need to get your Goodra relaoded. You could also potentially cut back to 3 copies of metal and include a copy of Energy Search to ensure you can get a metal energy when needed (you could use Irida to grab the Energy Search). 

If you make any changes to this list that you believe are improvements, please let me know!

UPDATE/EDITS: After further play testing and tinkering, I am now of the opinion that playing (3) basic metal energy is preferable to (4) Luminous Energy. I've also swapped out the Boss's Orders, Switch, and Bravery Charm for a play set of Cross Switcher.