Arcane Blademaster

Blade Channeling. Once per turn when the blademaster hits a target with a melee weapon attack, it can cast a cantrip which requires a spell attack roll against the target. This spell attack automatically hits.
Improved War Magic. When the blademaster uses an action to cast a spell, it may make one weapon attack as a bonus action.
Magic Resistance. The blademaster has advantage on saving throws against spells and other magical effects.
Magic Weapons. The blademaster’s weapon attacks are magical.
Steel Focus. The blademaster has advantage on Constitution saving throws made to maintain concentration on spells.
Superior Heavy Armor Master. While wearing heavy armor, the blademaster reduces any bludgeoning, piercing, or slashing damage taken from nonmagical weapons by 5.
Spellcasting. The arcane blademaster is a 20th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 19, +11 to hit with spell attacks). The arcane blademaster has the following wizard spells prepared:
Cantrips (at will): acid splash, blade ward, fire bolt, shocking grasp, true strike
1st level (4 slots): burning hands, charm person, magic missile, sleep
2nd level (3 slots): magic weapon, misty step, see invisibility
3rd level (3 slots): dispel magic, fireball, fly, lightning bolt, tongues
4th level (3 slots): fire shield, stoneskin, wall of fire
5th level (3 slots): cone of cold, conjure elemental, hold monster, telekinesis
6th level (2 slots): globe of invulnerability, sunbeam
7th level (2 slots): prismatic spray, teleport
8th level (1 slots): power word stun
9th level (1 slots): meteor swarm

Multiattack. The arcane blademaster makes four attacks.
Longsword. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 9 (1d8 + 5) slashing damage.
Longbow. Ranged Weapon Attack: +7 to hit, range 150/600 ft., one target. Hit: 5 (1d8 + 1) piercing damage.