Losing a creature a turn is a hard pill for an opponent to swallow, especially once it costs you no investment past the initial one mana and one card
Proliferate has always been a boon in these types of decks, and now with the mechanics card pool nearly doubled, we should expect to see counters happening even more
Giving your artifact creatures flying/lifelink can be strong, but you have to be built for proliferation effects, artifacts, and payoffs for the actual counters from proliferating
Given payoffs like Runaway Steam-Kin, Storm-Kiln Artist, and Young Pyromancer, you can have a lot of fun with this one
Despite being difficult to recur thanks to Ultima exiling itself on the stack, this combo is easily powerful enough to see play in Modern, and will likely be experimented with in control decks
Savage Thallid Savage Thallid is the timeshifted Feral Thallid, this time one mana cheaper, a little weaker, and with the missing Saproling-creation ability