For example, Solo Battles will feature decks related to the top chase cards, like Mega Charizard X EX, Mega Gengar EX, and so on
If a card is a hard counter (defined as a counterspell that could counter any spell without any restriction) it has to have in the mana cost
Not only does Pre-War Formalwear bring back a useful utility creature, but it also gives them a solid stat boost and vigilance to make them a threatening attacker and blocker
To "collect evidence N", exile cards with total mana value N or greater from your graveyard
You could play a kind of Modular deck using Artifacts such as Arcbound Fiend and Arcbound Slith, since you get to shift those +1/+1 counters around when they die, and then Ratchet, Field Medic can bring them back
To help narrow it down, we need to consider our rough sketch and see what cards fill that niche