You can give your opponents planeswalkers more loyalty, increase the number of +1/+1 counters on their creatures, or even just give them additional resource counters like oil counters
Brawl Not Legal Vintage Legal Timeless Not Legal Commander Legal Pauper Legal Oathbreaker Legal Penny Not Legal Toolbox Buy This Card Notes and Rules Information for Drain Life: Cost reducers can be used to reduce the X part of the mana cost
Four mana for a 1/5 isnt amazing, but it does start placing counters immediately, and potentially drawing cards too
Kaalia is has been among MTGs best commander decks for a long time because cheating mana costs is almost always broken, so with Kaalia you want the biggest, baddest creatures of the types you can find, like Avacyn, Angel of Hope or Vilis, Broker of Blood
Theres Room for a Little More Alright, weve seen the individual cards
Whenever you cast an Instant or a Sorcery, you get to create a 2/2 Blue Drake with flying