not too many combos are used in drafts but after playing so many nemesis drafts, ive found a few that have won me many games/matches
rupture + flowstone wall [pump the wall up as big as nessecary to kill as many creatures as needed]
(my favorite combo for nemesis drafts!! that has won me so many matches!)
Parralax nexus + rackling [remove all of their hand to make them take 3 damaga a turn for a few turns]
Assendant Evincar [Need i say more? this guy is the coolest thing to happen to draft since....something good]
A cool combo is Saproling Burst+Alter of Dementia. Make a token sac it, Make another sac it, and so on. That way you can remove 21 cards off of your opponents library.
Animate Land/Eradicate is pretty good against mono decks: Play Animate Land on one of your opponents lands then use Eradicate to remove that land and all others with the same name (that are in his hand, graveyard, and library) from the game.