Since it deals damage, All Will Be One can go infinite with cards like The Red Terror and Night Dealings, as they get a counter whenever damage is dealt to a player or permanent, which will then cause All Will Be One to trigger again, creating a loop that can do infinite damage
Generally speaking, two is the best pick for Talion, letting you hit the widest range for spells and creatures
Certainly a lot lower than skipping a two drop play in black
After seeing Galea last year, though, he really does highlight how jamming three colors together can be incredibly limiting for design, as theres only so much you can do without breaking cards wide open
For example, if an effect allows you to cast Spider spells from your graveyard, you can cast Amazing Spider-Man, but not Peter Parker
Merchant ScrollMerchant Scroll Merchant ScrollMerchant Scroll is a personal favorite tutor card from the early days of MTG