Activate Mairsil using Gilded Lotus' ability by tapping it, adding ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Activate Mairsil using Morphling's first ability by paying ({U} magic symbol) , untapping Mairsil.
Activate Mairsil using Quicksilver Elemental's ability by paying ({U} magic symbol) , causing Mairsil to gain all activated abilities of itself until end of turn.