Sources
CR
Type
Size
Alignment
Movement

Flux Blastseeker

Medium Humanoid (any race), Chaotic Neutral

Armor Class 12, 15 with mage armor
Hit Points 55 (10d8 + 10)
Speed 30 ft.
STR
10
+0
DEX
15
+2
CON
12
+1
INT
20
+5
WIS
9
-1
CHA
14
+2
Saving Throws DEX +5, INT +8
Skills Arcana +8, Perception +2
Senses passive Perception 12
Languages Common plus any one language
Challenge 5 (1,800 XP)

Traits

Fluxbending Overcast (Recharge 5–6). The blastseeker can create an additional effect immediately after casting a spell. Roll a d6 to determine the effect: 1-3. The blastseeker teleports, swapping places with a creature it can see within 30 feet of it. 4-6. The blastseeker and each creature within 10 feet of it must succeed on a DC 16 Constitution saving throw or take 11 (2d10) thunder damage.

Spellcasting

Innate Spellcasting. The blastseeker's innate spellcasting ability is Intelligence (spell save DC 16, +8 to hit with spell attacks). The blastseeker can innately cast the following spells, requiring no components other than its Izzet gear, which doesn't function for others:

1/day each: banishment, cone of cold, dimension door, fireball, ice storm

3/day each: mage armor (self only), scorching ray

Actions

Quarterstaff. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit:3 (1d6) bludgeoning damage, or 4 (1d8) bludgeoning damage if used with two hands.

Lore

While chemisters focus on inventing new tools, weapons, and other devices for the guild to use, the role of a blastseeker is to put those devices to work. Despite the name, not all such devices produce explosions, but all the most interesting ones (from the Izzet perspective) do.