Skiel can send the stolen Synchro equipped to it to the Graveyard to attack directly (and with its 2200 ATK, that's quite a heavy damage)
Granel can summon the stolen Synchro equipped to it, basically using it against its owner. And Granel gains ATK & DEF equal to half your LP, so it's great in decks that constantly raise LP.
Anoymous
:o