Sets started becoming smaller during the aughts, although 2007's Lorwyn bucked the trend with a mighty 301 cards
Although the Ally token created by the triggered ability is attacking, it was never declared as an attacking creature (for the purposes of abilities that trigger whenever a creature attacks, for example)
This matchup is already favorable before sideboard and gets much better afterwards
Aatchik, Emerald Radian Basri, Tomorrow's Champion Caelorna, Coral Tyrant Captain Howler, Sea Scourge Caradora, Heart of Alacria Daretti, Rocketeer Engineer Far Fortune, End Boss Gonti, Night Minister Hazoret, Godseeker Kalakscion, Hunger Tyrant Ketramose, the New Dawn Kolodin, Triumph Caster Lagorin, Soul of Alacria Loot, the Pathfinder Mendicant Core, Guidelight Mimeoplasm, Revered One Mu Yanling, Wind Rider Oviya, Automech Artisan Redshift, Rocketeer Chief Sab-Sunen, Luxa Embodied Samut, the Driving Force Sita Varma, Masked Racer Sundial, Dawn Tyrant Terrian, World Tyrant The Speed Demon Tyrox, Saurid Tyrant Vnwxt, Verbose Host Winter, Cursed Rider Zahur, Glory's Past
Whenever he or another legendary creature enters the battlefield under your control, the ring tempts you, which carries with it a slew of other abilities
