Wind-Up the Xyz

Get Magician out ASAP then use a Wind-Up's effect, preferably with Factory active to do the following:

Activate Magician's effect then chain it with Factory. Factory should resolve first.

Search Shark with Factory, then summon another copy of Magician using your first one's effect

Summon Shark when Magician comes out

Repeat until you have a full board then Xyz into whatever monster fits the situation.

 

Keep in mind the above is your most preferable opener. It may take an extra turn to get rolling, but that's how Wind-Ups work. If you have a couple Dogs out with Rescue Cat with Factory on the field, activate a Dog's effect and Factory will still search, but Dog's effect is negated.