Here is what one of the Synergy feat trees for A5e looks like:
BLADECHANTER
Prerequisites: 3 levels in fighter, 3 levels in wizard, Fighting Style (Two-Weapon Fighting)
Bladechanting is the art of unifying and maintaining intense physical and intellectual strains, allowing movement and thought to become one as a beautiful and deadly dance of blades.
If you wield a melee weapon in each hand, you may use them to perform seen spell components and as a spellcasting focus for wizard spells. In addition, whenever you are concentrating on a spell while using melee weapons as a spellcasting focus in this way, you enter a special trance-like state called bladechanting. If you lose concentration on your spell while bladechanting, you also stop bladechanting. While bladechanting you gain the following benefits:
- While you are wearing no armor, light armor, or medium armor, you gain a bonus to your Armor Class equal to your Intelligence modifier.
- Whenever you would need to make a concentration check to maintain a spell due to taking damage, you may spend 2 exertion to automatically succeed.
- When you hit a target with a melee weapon attack, you can use your reaction and choose a spell of 1st-level or higher, casting it through your weapon. The spell must have a casting time of 1 action, and target a single creature or have a range of Touch. If a spell cast in this way requires an attack roll and targets the same target as the triggering melee weapon attack, it also hits as part of that attack. You may choose not to deal damage with a melee weapon attack used to cast a spell.
WHIRLING INCANTOR
Prerequisites: Bladechanter feat
You train to move by thought and incant with your body’s flowing motion, becoming nearly unassailable as you whirl and dance, escaping fatal blows and seamlessly blending the lines between mind and body. While bladechanting you gain the following additional benefits:
- Your Speed increases by 10 feet.
- You gain a bonus to Dexterity checks and saving throws equal to your Intelligence modifier.
- You gain a bonus to Intelligence checks and saving throws equal to your Dexterity modifier.
- When you are targeted by an attack but before the attack is rolled, you may expend a spell slot to attempt a whirling arcane evasion. If you do, make a Dexterity saving throw and add a +2 bonus for every spell slot level above 1st spent this way. If this Dexterity saving throw exceeds the triggering attack roll the attack becomes a miss, and you may immediately move up to 10 feet in any direction. This movement does not provoke opportunity attacks.
ELDRITCH WHIRLWIND MASTER
Prerequisites: Whirling Incantor feat
With a blade’s sweep you pull and spin the arcane power, surrounding yourself in a cyclone of arcane energy as your spell's power tries to match the speed of your sword.
Whenever you use your reaction to cast a spell through a melee weapon attack using bladechanting, you may choose up to a number of additional targets for that spell equal to the spell level of the spell slot used to cast it. These additional targets must all be within 10 feet of you and are each treated as if they were the spell’s original target.
