It also reintroduced Trainer-classified cards (Trainer, Supporter, Stadium)
Most Psychatog and blue-green decks that started playing with Standstill ended up switching to Deep Analysis
However, Delighted Halfling only costs one green mana, makes all of your legendary spells uncounterable, and at its worst, it is just a generic mana rock
You can only use older cards if they feature the H, I, or J regulation marks required for the 2026 Standard format
Broadly speaking you want cycling costs at odds with the cost of the spell
--- Fluffal Pig / Scale 1 EARTH [Fairy / Pendulum / Effect] ATK/1300 DEF/500 ATK/1300 DEF/500 Pendulum Effect: During your Main Phase, if you control no monsters: You can add 1 Frightfur, Edge Imp or Fluffal Pendulum Monster from your Deck to your hand, except Fluffal Pig