Yuri was impressed by the skill shown by each fighter in the arena.  He knew Earth had amazing defenders, but anytime he fought alongside one, it always reminded him that he was never alone, that others fought the same fight he did.  Be it cultivating evil spirits, or fighting off invading otherworldly creatures bent on conquering Earth, he upheld the belief that everyone on Earth deserved freedom and equal right, and he would fight to his death their right to live and be free.  The swarm of butterflies did what they were meant to do.  Even with Sign Master figuring out the one true weakness of the perfect cube.  Had they been in the air, the cube would have no weakness, but since it was positioned on the ground, the ground was its weakness.

Yuri watched as Sign Master dove into a tunnel to avoid the hornet missiles and beautiful swirling mass of destruction from the Mech and Luna.  The butterflies managed to keep up with him, but he quickly popped up outside of the cube, a few of the butterflies managing to strike him, and two affixing to the creature's back as a sort of homing device, or rather an energy drain.  The two butterflies would not only send a beacon to Yuri, but they would slowly start to sap the energy from Sign Master to the point that would cause them to self-destruct.  

Yuri had made a mental note to ask Gou about the spirit wolf he's shifted into after Yuri had lowered the perfect cube.  Although they'd lost one of their allies, the Mech, Yuri knew it would only be a matter of time before he'd run into the owner of the machine, if only over a cup of coffee.  After watching Gou and Luna rush off to catch up with Sign Master, Yuri smirked.  The butterflies that had latched onto Sign Master's back would impale their proboscis into Sign Master just as Gou, in his spirit wolf form, would latch onto Sign Master's arm.  This would hide the fact that he'd been bitten three times.

Sign Master put up quite the fight against both Gou and Luna who were giving him more than what he bargained for, but Yuri hadn't yet appeared on the scene just yet.  Drifting through the breeze as a swarm of white luna moths, Yuri sped towards the battle.  He was able to catch up with Luna, Gou, and the Sign Master with relative ease, but decided to observe before interacting.  Gou was doing a great job at disabling one of Sign Master's arms, and Luna was hammering away at the side of Sign Master's helmet.  It was a comical scene, but Yuri knew they needed to act swiftly if they were going to put down the threat.  Yuri sped in front of the trio and took his normal form a bit ahead.  Even with two beings attached to him, Sign Master was still moving at a decent speed.

Yuri clapped his hands together and felt the air around him shift.  The butterflies that were draining Sign Master started to grow bigger and bigger.  They would be visible to Luna and Gou.  Sign Master would begin to feel his power slipping away, like a battery dying on an electronic device.  Yuri slowly pulled his hands apart and arcana sparked between his hands.

"[color=7bcdc8]Arcana: Thousand Arrows[/color]"

Arrow upon arrow appeared around him and Sign Master was on a collision course with him.

[i]When I tell you to let go, let go[/i] Yuri spoke telepathically to Luna and Gou.

As Sign Master neared, two luna moth shuriken struck his arm with the sign, slicing off the only usable hand he had.  When they were in range, Yuri spoke to Luna and Gou again to let go, and the arcana charged arrows surged forth like a wave, all targetting Sign Master.  At the same time, the butterflies would detonate further crippling Sign Master and decreasing his chances of survival.