Of course, the biggest upside of Zirda, the Dawnwaker is that its cost reduction applies to all permanents (see: the Basalt Monolith / Grim Monolith combos for Commander), and some artifact-based decks come very close to accidentally meeting Zirda, the Dawnwaker's companion restriction (for example, Modern Urza decks often only have Uro, Titan of Nature's Wrath as a permanent without an activated ability), so the unique wording on Zirda might open up new possibilities, compared to Biomancer's Familiar and Training Grounds, that will take time to explore
For example, if the chosen creature has defender, it could still end up being an attacking creature this way
There are 5 common cards (7.1%) from the Magic: The Gathering | Marvel's Spider-Man Eternal-legal set (SPE) that can be found in these slots
A green sorcery for four mana, this spell provides all creatures under its caster's control with +1/+1, trample, and infect