HeiHei allows an opposing item to remain exerted, so any item that has to exert itself for its effect would not be able to be used
That said, Tarkir: Dragonstorm gave us a large number of Abzan cards, with a notable subset that leans heavily into toughness-matters strategies
If you notice black decks keep doing well and red decks seem to struggle, swap out some of the weaker red cards for stronger options, and nerf the black archetypes, for example
The deck's included Clan Crafter background synergizes well, but the green Raised by Giants background is probably a better dedicated choice if players want to run Baeloth as their commander
Lore, symbolised by the weighted diamonds (present in the O of Lorcana), is gained by exerting the character
This might hit $2-$3 if it does become an important sideboard card, but thats its top end