Whenever one or more creatures or artifacts you control are put into the graveyard from the battlefield, draw a card
However, there are better options like Dead Weight or Disfigure which offer similar effects for the same or lower cost, making Weakness less likely to see play in competitive decks
If the target creature has become untapped as the last ability tries to resolve, Motion Sickness stays attached to the creature it's already on
Consider that Mana Leak is now considered slightly too powerful, maybe just make this a Mana leak with the UU casting cost
Its a very simple strategy: Deal direct damage early to reap massive discounts via your commander
All cards must be singleton (one of each, no duplicates), and everything in the preconstructed deck must match the color identity of your commander