For cards like Ash, Party Crasher, triggering her celebration ability will put a +1/+1 counter on her when she attacks
2 Bloodthirsty Conqueror No Pain, No Gain 5 Mana Cost in Black Creature The only real issue with Bloodthirsty Conqueror is its mana cost, being an expensive card to play in a color with fewer ways to ramp
The next-easiest is also a one-card combo: Phyrexian Devourer (+ Jarad)
The least of these are Companion of the Trials and Gideon's Company, a pair of creatures with irrelevant activated abilities contingent on controlling Gideons
You don't need to make another Myr Battlesphere/Wurmcoil Engine each turn to have these be good, although that is certainly something they can do
You love the thrill of the draft As was the case with MTGs Warhammer 40k crossover, Wizards of the Coast have chosen not to embrace a booster-based product line