He can superheat his sabre by scraping it against the Scald Tooth Dagger. This greatly enhances its attack speed and makes its draconic attacks resemble those serpents’ fiery might even more.
The sabre’s aura can send out waves of energy that coil and twist like a wyvern. If Daniel threw his dagger, he could follow it up with a strike from the sabre, carrying the dagger along the dragon’s path. Gives the dagger some extra force and allows him to change its trajectory.
As for the musket… That’s for when things get serious. For when you can’t afford to be cool and flashy anymore, and you just need to get the job done.
Interesting… Honestly, with complete control over someone’s senses, you probably wouldn’t need any fancy tactics.
I suppose he could try freezing his opponents in place with crystals to ensure he’s able to infect them with the blessing.
He could give crystal weapons and armor to the people he controls, and manipulate their reality to eventually convert them into his pawns to throw into battle. Since magic can still be correctly sensed, this would likely only work on weak people who can’t sense well, or at all.
I imagine he would impress people by doing a bunch of fancy maneuvers and flourishing with the weapons he conjures. If he’s not good at it, maybe he would use illusions to make you see otherwise, to save some pride.
Is this just the canon AOMC? 
That’s fun honestly. But actually I’ve already made a strategy for them a while back, which you can read here:
I think it still holds up pretty well, I doubt I could think of anything better anytime soon.
As for this… Very interesting. This concept is awesome, especially visually. Fire that thrives on water? Quite fun.
I imagine they would use very large-radius attacks. The fire is so potent and agonizing, just a single spark of it hitting could change the entire flow of the fight. There’s no such thing as “spread too thin.” Even a weak attack landing would probably greatly hinder the opponent’s ability to battle due to the pain and burning. Not to mention it could spread along their clothing and grow bigger.
They could spread water puddles everywhere with Sailor Style and their Sunken Sword. The more conduits for their fire, the better. Spirit Rain could be a favored rite of theirs. It comes from the Staff of Night, which they don’t have, but since it’s a basic rite it is compatible with the Eagle Patrimony, so I do believe they could learn it one way or another.
For mobility, they could ride on Spirit Wall like a surfboard, sweeping across floods and waves made from their own magic. They strike with fast, fluid movements of Sailor Style. You can barely see their body through the torrent of their own burning water.
I like this one! Any character that uses spirit energy is always extra fun to work with.
According to the lore doc, powerful Oracles can cause bodily alterations using their control over spirit energy. So, biomancy, essentially. What if Abel made use of that in a very haphazard way?
His attacks carry spirit energy that basically randomizes your biology, causing all manner of awful mutations. Lightning bolts from his Eagle Patrimony inflicts an outbreak of rot in the pattern of lichtenberg scars, as if a moldy plant were grafted onto your skin. Spirit-imbued magma melts your flesh, but not like any normal fire should. It’s wrong, distorted. You don’t know what to make of it. You only wish you’d never seen it.
Getting hit by this guy has a chance to turn you into eldritch horror on the spot, pretty much. Of course he would only reserve this to be used on the truly evil, but it’s horrifying all the same. Certainly adds to his intimidation factor. Who would want to cross this man, not knowing what you might come out as? Whether you’ll still be you?
Morally, it’s very questionable, but I could see someone truly ruthless resorting to it. The message is loud and clear to all those who do evil on these seas: If you choose to twist and break for your own selfish gain, to tarnish peace with every step you take, to taint life itself, you will be made to look as rotten on the outside as you are on the inside. So watch your every act, or someone else will.