A few people asked me to move my guide from the old forums so I decided to remake it and place it here. Feel free to use it or change it up, but I personally I feel this is the most optimal rotation you can possibly get.
DPS Flow Chart during Enhance Bolt: Hunting party, build 180 sp, enhance bolt, double hollow, perforate, double hollow, six shooter, double hollow, perforate, double hollow, six shooter, etc. until enhance bolt is off cooldown. Sometimes if your speed is really high, you may end up in a scenario where all of your skills are on CD. In that case, pewpewpew away.
DPS Flow Chart when Enhance Bolt is off CD: You should have alot of sp left over from hunting party and enhanced perforate + cat statue. Bolt Storm and Nuke accordingly, trying to get headshots as much as possible with bolt storm. Six shooter is a viable move still even without enhance bolt and perforate if you land mostly headshots. You should bolt storm before nuking since it builds you more sp back but that depends on the boss (ie. Succubus Queen, Iset, Lugh, etc.). Try to leave yourself at least 250 sp so when you enhance bolt you waste no time and can go into that flowchart listed above immediately. Greater cat statue syncs very nicely with hunting party. These should ALWAYS be used in conjunction.
1. In certain scenarios, sometimes you will find yourself in a situation where the boss is down and you are still in enhance bolt. If you can manage to get the majority of your shots headshots, then I would definitely go with using bolt storm even though it doesnt receive any buffs from enhance bolt. Bolt storm is actually his most damaging move if 80-100% of the hits are headshots. Even if none are headshot it still does tremendous damage.
2. ALWAYS USE HUNTING PARTY. I can't stress that enough. Many many many kais fail to do this and its frustrating since with just two kais you can keep hunting party up 100% of the time. Hunting party actually boosts kai's own damage considerably since he has much better sp management.
3. Speed is important on Gun Kai. Aim for 40-50 to be comfortable. Higher is better as you build more sp with faster bolt shooting, but the benefits diminish the higher you go since kai is ultimately restricted by cooldowns on his active skills. Still, at high speeds he feels very fluid and dynamic.
Damage: Hollow Shot, Spin Smash and Six Shooter. Damage can be put on Perforate if your speed is very high, which means your SP gain is higher from faster left click shooting. 55+ should be when you can debate whether to use Damage or SP.
SP reduction: Hunting Party and Bolt Storm. SP reduction can be put on Perforate if your speed is mediocre or slow. I would say under 40 you should definitely go SP reduction.
Cooldown reduction: Enhance Bolt and Massive Impact. Enhance bolt is an absolute must.
The inclusion of enhance bolt and reworkin of his active skills has made kai more complex and deeper mechanic-wise. He has much more things to keep track of and alot of options to choose from. He isnt hard to do damage with or to survive (buff to dodge was op), but playing him at a higher level has become harder and increased the gap between a bad kai, a good kai and an amazing kai. There are tons of people who dismiss kai has a baby mode and easy character and thus feel he is one dimensional and takes very little effort. Therefore they do not try and they don't explore his rather interesting and powerful kit.
Demonstration of Optimal Rotation For Kai: Zecallion Solo
Sorry for the low quality, I have since then figured how to record in higher quality.