In the vast majority of games, the life that your opponent gains from you nuking their creatures with Swords to Plowshares will not amount to much, unless theyre playing a black deck with life-to-resource cards (watch out for Toxic Deluge or worse, Yawgmoths Bargain !) Swords to Plowshares isnt a particularly expensive card, and its very easy to find
Tokens Recent addition Securitron Squadron has shown that token-oriented strategies can be quite powerful in the Vintage Cube environment
Having such a hefty ability cost (or in Kenriths case, such a heft of different abilities) means these activated effects must be extremely impactful
Seven of the 15 mythics in the set are worth more than the $10 MSRP of the pack they come from, and the high end is doing just fine with Jace, the Mind Sculptor, Imperial Recruiter, Ensnaring Bridge, and Chalice of the Void, but after the seven good mythics, there's a massive drop off from Animar, Soul of Elements at around $13 to Gisela, Blade of Goldnight at under $4
Im sure this will be yet another weird Commander buildaround, but I think Niv-Mizzet, Guildpact mostly wants to hang out in the graveyard waiting to get pulled along by your Lazav, Wearer of Faces, like Weekend at Bernies 2: Guildpact Edition
Seeing that 3 of those 4 cards are Instants, you'll most often just be casting them at the end of an opponent's turn, then drawing it immediately