Summon: Titan I think Crystalline Armor is underrated, but if I spend one more mana, I get some self-mill, get a potentially huge ramp in land, and a one-time Crystalline Armor
Plus, we're not going to mess with the mana base
Deep Forest Hermit breaks the immersion a bit, but it makes and pumps Squirrels, so the Elf Druid typeline gets a pass
Each creature that enters the battlefield under your opponents control, from Rogue Refiners to Thopter tokens, will represent a two-point life swing, which can really add up over the course of the game, making this two-mana investment a critical card against the current best deck in the format
Then you discard a single card
Beyond her popularity as a Final Fantasy character, Yshtola is remarkably powerful in Commander, influencing price spikes on cards like Ophidian Eye, Helm of the Ghastlord, and Snuff Out recently