mtg discard filler card from LCI : r/magicTCG Mtg Filler Card | eBay

The cards that could do so had to be phrased as to avoid suggesting that one could loop mana abilities for infinite mana - as mana abilities don't use the stack, copy effects cannot "locate" such an ability

Rule 614.11b doesnt apply for Sylvan Librarys ability, because a player doesnt perform actions on the drawn cards

We did this in two ways

Mox Sapphire is probably the most famous of the cycle and a staple of Vintage decks that, for the most part, use many blue cards to support Force of Will and other means of free protection, in addition to being the color of timeless staples like Tinker and Ancestral Recall

The extra removal when this Balrog dies nearly guarantees that you trade with another commander, or that you nab another as part of the collateral damage