Always try to start with at least 1 Array of Revealing Light and 1 Guardian Statue/Medusa Worm in your hand.
With Array of Revealing Light always declare Spellcaster-type.
The main idea is that Ishizu cannot attack with her Spellcaster-type monsters the turn she summons them. You will then use Guardian Statue/Medusa Worm to remove them from the field during your turn, and then flip your monster face-down again for reuse. Make sure you clear Ishizu's field every turn.
It is best to use Guardian Statue on Gravekeeper's Recruiter so that Ishizu Does not deck out first.
Use A Feint Plan, Windstorm of Etaqua, and Curse of Anubis to stall with your set monster.
It is best to always have 2 Flip monsters on the field.
On your final turn, flip any Guardian Statue/Medusa Worm you have and clear Ishizu's field. Acvtivate Temple of the Kings then tribute into Mythical Beast Serket.
With Temple of the King's effect, send it and Serket to the graveyard to special summon Blue-Eyes Ultimate Dragon.
Use Double Summon to summon Gravekeeper's Vassal.
Remember to use Anti-Magic Arrows during your final Battle Phase.
This is de Deck I am using against this girl, your only nemesis is Oracle, so you need to have cards to negate its effect like chalice, order of the emperor or divine wrath. Even you can use memory loss. Also Zombie world is a good option. 7k-8k 95% effective
Why do you assume he owns a phone? Or a toilet bowl?
kiseitai/massivemorph ra works great, you only have to mind that he can tribute all his monsters and ruin massivemorph or kiseitais. save them till he tributes summon something then use you massivemorphs, and 1 kiseitai, you only need 2 kiseitais anyways, maybe 1. even if you have 2 massiveporph is still fine since ou can survive with temple.
This is the deck that use against her:
3x Guardian Statue
3x Medusa Worm
3x Planet Pathfinder
1x Man-Eater Bug
3x A Feint Plan
1x Windstorm of Etaqua
1x Anti-Magic Arrows
1x Nobleman of Extermination
1x Infinite Cards
2x Array of Revealing Light
The Idea is to destroy or bounce her monster with Worm and Statue if u summon Statue Early, then don't use Worm's effect since she might activate Rite of Spirit to spec. Summ. Her monster from GY even I put Nobleman and Anti-Magic. Activate Infinite Cards ASAP so Ishizu can't discard any monster to GY
I use this deck, the key is to play Zombie World as soon as possible. This keeps her from Tribute Summoning Oracle, and the other two. Then Just destroy Necrovalley when it shows up, and try to floodgate Shaman and Visionary. If you have the "Posthumous Army" Skill, I'd replace planet pathfinder, Zombie world, and a twister/typhoon with 3 Field Barriers. I'd say this works about 70%, but maybe I've just been lucky.