Maskwood Nexus works on Creatures you control, Creature spells you have on the stack, and cards you own that aren't on the battlefield
Eldrazi Linebreaker Im like 90% sure that Eldrazi Linebreaker is a football reference, but I know nothing about sports and thats just fine with me
A three mana 'walker is as cheap as you'll typically get, and many of the best planeswalkers of all time, like Liliana of the Veil, are three mana
If the spell shares both a color and a mana value with the imprinted card, Thought Prison deals 2 damage, not 4
This works best at the highest power levels, where players throw around spells like Force of Will and various Moxen that Lavinia counters
The bit of set up is needing a good creature to attack with and a counter somewhere on your board