EXVC Week - Unknown Synchron: It does stuff.

If your opponent controls a monster and you control no monsters, you can Special Summon this card from your hand. Each player can only use the effect of "Unknown Synchron" once per Duel.

Machine/Tuner

It's other stats don't really matter.

It's level one-ness makes it combo well with Machina Fortress in Karakuri Machiner's Plant. You can Synchro for Bureido and continue with your combos. It's machine-ness does almost nothing. You can discard it for Fortress. And that's about it. But is it only good in Karakuri?

No. it's splashable in almost everything. You can make new levels of Synchros with a bit of forethought in almost any deck. It's really good in token-spamming decks, too.

:D