Context: I play Swain when Singed is banned. I am d4 in OCE server. Similar to Quas, I will poke enemy if possible, but my objective is to get as many cs as I can in laning phase. This is because Swain’s winning condition is to wait till he is scaled up with items and then start a good teamfight. Swain’s winning condition is never trying to snowball from laning phase.

Phase Rush: Phase Rush is a better alternative than Glacial slow. Of course you will lack the damage from comet and aery but i find it acceptable since its hard to kill enemy laner in high elo unless they make a mistake. Also speed boost allows you to move away from minion aggro and bad trade easily. Phase Rush is very useful in teamfight too.

Presence of Mind: your mana is no longer an issue in teamfight. Also you can spam spells as many as possible in lane which compensates the loss of DFT.