Aerith, Last Ancient offers a lifegain payoff you will almost never pull off in an actual game because aside from Sephiroth, Fallen Hero or Wrecking Ball Arm there's no other way to reliably get her to 7 power and very little lifegain in the deck otherwise
The power of Sagas is pretty obviousyou spend the mana to get the enchantment once, get a bit of value right away when it enters the battlefield, and then get free value for the next two turns
I already mentioned ManamorphoseManamorphose and Kitchen FinksKitchen Finks in the intro, but what about Master WarcraftMaster Warcraft and Murderous RedcapMurderous Redcap
If you need a wider board, try Yorion, Sky Nomad
This has a sacrifice trigger for any artifact you control, not just tokens, by the by