Activate Myr Welder using Worn Powerstone's ability by tapping it, adding
Activate Myr Welder using Staff of Domination's first ability by paying , untapping it.
Repeat.

Once you have infinite mana, you can use any other ability from Staff of Domination in step 1 instead.

Activate Trazyn using Worn Powerstone's ability by tapping it, adding .
Activate Trazyn using Pili-Pala's ability by paying and untapping it, adding one mana of any color.
Repeat.

Activate Trazyn using Worn Powerstone's ability by tapping it, adding .
Activate Trazyn using Staff of Domination's first ability by paying , untapping it.
Repeat.

Once you have infinite mana, you can use Staff of Domination's other abilities via Trazyn.

Activate Trazyn using Worn Powerstone's ability by tapping it, adding .
Activate Trazyn using Farmstead Gleaner's ability by paying and untapping it, putting a +1/+1 counter on Trazyn.
Repeat.

Activate Worn Powerstone by tapping it, adding .
Activate Voltaic Key by paying and tapping it, targeting Worn Powerstone.
Locus of Enlightenment triggers, copying Voltaic Key's ability, targeting Voltaic Key.
Resolve both Voltaic Key abilities, untapping it and Worn Powerstone.
Repeat.