Quote from Al_Z_Heimer »Deftblade Elite is amazing. Early it can trade off strong utility X/1s like Undertaker or Fireslinger. It also goes super nuts with auras or equipments. Drawn later in the game it's a brick wall that can roadblock every ground beater.
Soul Manipulation is super strong. Dimir is stacked as hell, but this is definitely a valid option. It's a straight up 2 for 1, that also gives you the card selection of choosing whatever creature you would like to return.
Apropos Prowess in general (e.g. Sanguinary Mage), it's simply a really bad mechanic. To trigger it constantly it often requires you to sequence your spells badly. Usually you want to play your instants an sorceries at the latest possible moment (2nd main or your opponents end step) and keep mana open to deny your opponent the information what you might have in hand. Even though theoretically it sounds nice to use any kind of noncreature spell as a kind of free combat trick there are actually very little spells you want to play during combat just to get a tiny +1/+1 push.
It doesn't sound that helpful, but my best advise is to simply use cube-comparison-tool from cubetutor. Simply compare your cube with updated lists from other people (link in my signature) and see which cards no one else is running and think why that might be and also see good alternatives.
Fireslinger can just tap in response to the untap and kill elite. And if you really want undertaker not to die you can also just activate its pitch ability. The way Provoke is worded any utility creature that taps to do the utility can always escape being killed.
If you want a 1-drop that kills other 1-drops, javelineers is way better.