one card win conditions mtg A blue condition : r/custommagic Instant-Win Condition - TV Tropes

While its true the stat-line is a bit awkward, the Aristocrats activated ability is incredibly strong

Cards that add +1/+1 counters are getting much more efficient, so between Innkeeper's Talent and Tribute to the World Tree, you can have a pretty powerful Warcaller leading your troops

Priest of Forgotten Gods has a lot of synergy in this deck

It is much narrower than Mox and Sol Ring as you need support cards for it to reliably tap for loads

The fact that Vivi deals passive damage while growing and generating the mana to cast tons of spells (or really big spells) all added up to a monstrously broken experience

That's a starting point