On the contrary, I don't see why the combo wouldn't work, it makes sense. Also, I don't see why Smack Down shouldn't be performed using a girder. Anyways, the Round.
Round 5 Start
Dummy007 XAOO (4 Chills Remaining)

Septimus Heap
HP:
48
Energy:
74
Atk: Rank 3
Def: Rank 3
SpA: Rank 3
SpD: Rank 3
Speed: 47
Size Class: 3
Weight Class: 4
Base Rank Total: 16
No Changes
deadfox081 XAOO

Puncha
HP:
100
Energy:
74
Atk: Rank 4
Def: Rank 2
SpA: Rank 1
SpD: Rank 3
Speed: 40
Size Class: 2
Weight Class: 3
Base Rank Total: 16
Sheer Force Activated
ROUND FIVE: RPing Is Cool...
So, it's time for Round 5, is it? Well, here goes...
And Puncha begins with a fast, powerful thrust towards Septimus Heap & then knocks him into the air with a powerful Iron Fist. After knocking Septimus Heap high into the air Puncha then makes a powerful thrust up & then somersaults & wallops Septimus Heap with an almighty thrust of his trusty girder, sending Septimus Heap crashing heavily through a hovering platform, breaking the platform into shreds as Septimus Heap crashes head-first into the ground, taking more damage. Ouch! Septimus Heap then lurched & got up before firing a red beam into the sky, making the sunlight even harsher than before, making the crowd & the trainers go for sunglasses.
Septimus Heap, at this point, decided that it was a great time to have a break, using lis leaves to put him through a process of photosynthesis. This went uninterrupted as Puncha was too exhausted to stop the process from completing. A few minutes later, & Septimus Heap was done, feeling significantly healthier than before & looks like he is raring to fight again!
Puncha then got up & took hold of the rubble that was formerly a platform, scooped most of it into his girder & then somersaulted into the air, chucking the rubble on Septimus Heap's head. Septimus Heap took the brunt of the damage, & turned it into energy after bracing the overhead rubble & used this energy against Puncha, focusing the energy to into a powerful fist which Puncha is walloped by for some mighty damage.
Round End & as the two combatants lick their wounds, it seems that the crowd had enjoyed the round's action, despite the fast-increasing damage bill. Now it's time for someone else to issue a challenge to these two combatants...
Round 5 End
THE SUNLIGHT IS HARSH... (3)
Dummy007 XAOO (4 Chills Remaining, 4 Recoveries Remaining)

Septimus Heap
HP:
34
Energy:
39
Atk: Rank 3
Def: Rank 3
SpA: Rank 3
SpD: Rank 3
Speed: 47
Size Class: 3
Weight Class: 4
Base Rank Total: 16
Grounded (3)
deadfox081 XAOO

Puncha
HP:
70
Energy:
59
Atk: Rank 4
Def: Rank 2
SpA: Rank 1
SpD: Rank 3
Speed: 40
Size Class: 2
Weight Class: 3
Base Rank Total: 16
Sheer Force Activated

"I want to see these guys tire before they become more bruised!
Use More Energy than the amount of damage you deal. Do not Spam a move three times, nor may you use more than one non-attacking move."
ORDER
Dummy007 issues actions.
deadfox081 issues actions.
I ref.