A good combo for this build would be throwing a Great Chaos Fireball on your opponent feet and then using a Great Combustion.
Another combo is similar but this time throw a Great Chaos Fireball and when your opponent is stun use Wrath of the Gods and finish with a quick Great Combustion, but before doing this combo make sure you have both Darkmoon talisman and the ascended Flame out.
Remember to use Sunlight Blade first and then when it runs out switch to your ascended Flame when you need it.
Use Gold Pine Resin when you don't have any more Great Chaos Fireball or Great Combustion because it will increase the damage of the Iaito.
You don't have to use the Red Tearstone Ring, so the second ring slot is your choice.
Please try out this build it is a really good PvP build.