The ability to make permanent tokens is huge, and Menace and Haste make it pretty easy to get the triggered ability online
An instant or sorcery spell with lifelink that causes another source to deal damage won't cause its controller to gain life
It makes any counterspell a 3-for-1, but Commander players often have bigger threats to target, and seeing three cards is a lot
The explosive tempo of Legacy and Vintage, unique among Constructed formats, comes from their avenues of transmuting cards into mana Black Lotus, the Moxen, Channel, Lions Eye Diamond, Dark Ritual, Lotus Petal, Grim Monolith, Cloudpost the list goes on
The Planeswalker essentially forces your opponent to play at sorcery speed, and gives your sorceries Flash as an uptick
Trial of a Time Lord Sagas are such an interesting design, but I typically find it hard to want to play them without getting immediate value out of them