After a little exploring, it became clear that making tokens of existing creatures would both fill the nostalgia theme and the innovation/future theme
Borderless Double-Faced Sagas By the time we meet Aang in the original series, the prior Avatars and their foes are mythical figures
Accusations and heated language never help the situation and can be embarassing if the card turns out to be real, which is more often than not the case.
Alternatively, Krark-Clan Ironworks will let you make infinite colorless mana for a Walking Ballista win
If you want to build competitive decks The competitive SRs (Yamato, Boa Hancock, Sakazuki, Luffy) are obtainable within 12 English boxes with reasonable luck given the higher per-box SR rate, or more reliably through singles
Heroic Intervention Not quite Teferi's Protection, but still a super powerful card to save your stuff from all kinds of removal