If a noncreature permanent is detained and later turns into a creature, it won't be able to attack or block
We can also run single-card strategies like Elesh Norn, Grand Cenobite, which wipes out small creatures, or Elesh Norn, which costs folks for damaging us or our creatures while providing itself the ability to do busted stuff by becoming an enchantment named The Argent Etchings
Even if you don't have enough creatures to make this a counterspell, you can always pay more into the X part of the casting cost to make it one
To help you with brewing, heres a list of some spell mechanics that work with Vegas ability: Foretell Flashback Jump-start Suspend Cascade With Vega on board, Ravenform will draw a card while exiling, flashing back Deep Analysis now draws three cards, and Sakashimas Protege somehow generates even more value
Fabrication Foundrys combination of efficient ramp plus secondary utility is not something you see very often