To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as a flashback cost), add any cost increases (such as kicker costs), then apply any cost reductions (such as that of Urianger Augurelt's last ability)
Tourach, Dread Cantor Tourach, Dread Cantor requires a heavy black deck to function due to the color-intensive kicker cost, but you get a powerful three-for-one if you manage it
Overload [cost] means "You may choose to pay [cost] rather than pay this spell's mana cost" and "If you chose to pay this spell's overload cost, change its text by replacing all instances of the word 'target' with the word 'each.'" If you don't pay the overload cost of a spell with overload, that spell will have a single target
Take the pain and do it
Yuna, Hope of Spira, gives her and all of your enchantment creatures (not just summons) trample, lifelink, and ward 2