This swain build is all about sustaining team fights. This is mainly a top lane build and probably wont do so well mid. the regen runes should give you enough mana regen to fight without needing to rush mana items or regen items. swain needs damage output items and he needs them fast. also, the longer you can stay in a team fight, the better. Until you get either blue buff or rod of ages, though, you cant really stay in your ult for too long. maybe 10 to 15 seconds max, or you'll run out of mana too fast and not be able to fight anymore. Once swain is out of mana, he's out of the fight. the combo of will of the ancients and spirit visage will give you so much heal when you ult is on as well. you're getting a massive increase on the healing from your ult, as well as increased spell vamp on all of your abilities. remember to always throw torment on the ap carries too, their burst is your weakness and will destroy you. If the game goes on long enough to complete your build, sell spirit visage and buy an abyssal scepter