If a resolving spell or ability says that a player may give counters to that creature or player, that player cant choose to do so
Courser of Kruphix adds another line of defense, giving you some lifegain here and there to ensure you live longer, and you can play lands from the top of your deck which is a strong source of card advantage and filtering
Author's note: These lists are in alphabetical order
If one or more of its targets are legal when it tries to resolve, the spell will resolve and affect only those legal targets
Obviously Tawnos, Urza's Apprentice + mana rocks + Paradox Engine is infinite mana, but saying "combos with Paradox Engine" is about as surprising as saying "this planeswalker is really good with Doubling Season!" There's more obscure combos out there though, such as pairing Tawnos with Sands of Time for infinite untaps / mana -- yes, Sands of Time is a real card that now has actual Commander potential
Centering and edge wear are common on this print, so high grades are scarcer than the raw population suggests