As for Decimator, uncounterable on your Overrun is very nice against the blue decks
End Hostilities is already an effective sweeper in Limited, but Duneblast takes it to the next level, both in terms of effectiveness and mana value
Enchanted creature doesn't untap during its controller's untap step
Griselbrand Perhaps the most infamous life payment card (next to Channel, maybe?), Griselbrand is the gold standard when you want to reanimate, Sneak Attack, or otherwise cheat creatures into play
Desynchronization An instant speed board wipe is always welcome, even one as limited as Desynchronization, which could actually whiff in an EDH game with the proliferating number of legendary creatures out there
Let me know which mechanic you'd like to build an entire deck around on the next Mechanically Minded