When Dragonlord Atarka enters, it deals 5 damage divided as you choose among any number of target creatures and/or planeswalkers your opponents control.
Ramp hard into Dragonlord Atarka to clear blockers and value creatures with her 5-damage ETB, then close fast with a big flying trampler and a wide Gruul board. Most games are won by ramping into fatties, recurring Atarka's ETB via blink/reanimation, and beating down before opponents stabilize.
Powerful ETB that doubles as removal and a planeswalker check, repeatable with blink/flicker
Evasive flying trample body that ends games quickly
Lives in green's best ramp and red's best damage, so it deploys early and threatens broadly
Strong against go-wide/token strategies and superfriends decks
7 mana means a slow start if ramp doesn't show up
Only damages opponents' creatures/planeswalkers — useless against pure control or pillowfort with no targets
No card advantage built in; can run out of gas
Vulnerable to spot removal and counterspells right as you tap out
No native protection or recursion in the command zone