The Dragonian Tournament is soon, and your dragon wife nags you to death until you agree to participate in it. Your possible opponents are:
A. A Dark Dragon with exceptional physical prowess, very fast, high physical & fire resistance. No other known weaknesses or strengths.
B. Two dragon sisters, one blue & one red. The blue one is a very tall, very strong dragon that fights berserk style, she lashes at the target hard and fast and she cannot be stunned or brought out of action until she is completely defeated. The red one is a magician specializing in fire. She prefers to attack from range.
C. A squad of lizard gunmen (or more correctly gunwomen). They can't fly but they have good aim, all armed with assault and sniper rifles. Your dragon wife has good def but, continuous fire will bring her down in several seconds.
D. A malef. She's a weird character, she doesn't use any weapons or here black fire, but has strong status magic. Against your wife she'll only cause light debuffs, but if used on you, her magic might make you completely forget all about the combat and immediately submit to her will. She isn't particularly strong in physical combat (for a dragon) but she has 100% immunity to physical attacks.
You have a bunch of tools & weapons to choose from but you cannot take more than three and you can have only one weapon. You cannot go into battle without a gun, either.
* A .50cal anti-materiel rifle. Fires explosive rounds (Phys + Fire). Thanks to monster magic, it can bring down a dragon in one shot.
* A mounted machinegun turret. Fires rifle rounds at a very high rate (like 1200 RPM). Does loads of damage but you can't move it once installed. Shoots bullets by default but if you have a magic crystal, you can infuse the ammunition so it would also deal the given element damage.
* A power armor that grants you extremely high agility, speed, and evasion. You are faster than even dragons, but not stronger.
* A homing missile launcher with magical charge. You can infuse it with any magic you possess. However, it's pretty slow so a dragon could dodge and outrun it in air. No default damage, it's useless without a magic crystal.
* An ice magic crystal. Ice magic slows down targets and makes them less effective in combat. However, it's pretty weak (about 1/3 of the damage dealt physically)
* A poison magic crystal. Nullifies any and all damage from the weapon that uses it but if it hits a target, it'll go down in 2 minutes or less guaranteed.
* An earth magical crystal. Rather than doing something to the weapon, it instead protects the wielder, making them immune to all damage. Status effects don't count.
* A lightning crystal. Requires a weapon that can penetrate thee dragon's skin as its magic would be otherwise reflected off the scales.
* A life crystal. Enables the wielder to heal themselves and their ally. Cannot heal both at the same time.
* An Energy Cannon. By default it won't do anything, it requires some sort of magic to be applied to it so it would become useful. Earth crystals make it do physical damage. Unlike the missile launcher it's a hitscan weapon, you can't dodge or outrun it if it hits you.
* An Invisibility Cloak. Can conceal the wielder from the observers, but if the wielders makes one attack move, the invisibility magic will be rendered useless.
* The Reflector. Nullifies all magic used against the wielder, status effects included. Does nothing against the physical damage.
There are additional premises applying to the fight.
* If your attack has more than one damage type (let's say physical and ice) and the target has resistance against either, both kinds of damage are affected by that resistance.
* Your dragon wife is strong enough to last at least two minutes against any opponent.
* If one contestant goes down, you both lose regardless of who was downed.
* Your wife has innate fire magic. No crystals are needed.
* Malef magic won't work on you unless you have direct eye contact.
Your goal is to Win No Matter What. Loss is unacceptable. Yes you cannot lose to the hot malef even if that means a hot steamy femdom threesome.
Now try to arrange this fight so you will win no matter what the opponent is.