Most games I've seen that use a sycthe as a Melee weapon use it more as a mix of Great-Axe & long-pole combat (with Sycthe's that have the S shape handle but lose the 2 hand-holds that would have been needed to use it as its origional tool, a grass cutter)

Granted in the few games I've seen use a Sycthe only Zazamel (not sure on spelling) from Soul Caliber used his in a semi-believable way, as a hook for grabs & using 2h axe/long-pole short range CQC. other times I've seen a Sycthe is as a staff for Nerco-mancer mages or undead farmer zombies (wnich is the best still believable way)