Here is the 5e version of Isumi I am using. I thought the grenadier and sniper traits fits Isumi thematically quite well. She is also a great boon to my under-leveled party. I like Isumi, she has a very John Carter of Mars feel to her.
“I am Isuma, and I am from a distant world. This land is strange to me, as I must be strange to you, but it does good that we can talk. I need allies. I need companions. Those who took my previous ones still dwell to the west, and they still defile the bodies of my kin. I need your aid in securing revenge. Do this, and I shall aid you as well, as best I can.”
Medium humanoid (kasatha), lawful neutral
Armour Class 18 (+1 aurumvorax hide armour of invulnerability, hard light shield)
Hit Points 140 (14d8 + 56)
STR 15 (+2) DEX 18 (+4) CON 18 (+4)
INT 14 (+2) WIS 14 (+2) CHA 15 (+2)
Skills cybertheurgy +6, survival +6
Saving Throws Con +8, Int +5, Wis +5
Senses passive Perception 15
Languages Gothic (High and Low), Kasatha
Challenge 10 (5,900 XP)
Brave. Isumi has advantage on saving throws against being frightened.
Grenadier. Isumi is an expert with the use of grenades and other explosives. She may re-roll 1s when using explosives (including grenades). She must take the result of the reroll.
Sniper. Isumi has mastered the use of rifles. Attacking at long range doesn’t impose disadvantage, she may ignore half and three-quarter cover, she may also take a -5 penalty to hit to gain +10 damage. Finally when using a rifle she gains +2 to hit and may count her dexterity bonus as extra damage (included).
Four Arms. Isumi can make four melee attacks or two ranged attacks.
Masterwork Bone Dagger. Melee or Ranged Weapon Attack: +8 to hit, reach 5 ft. and range 20/60 ft ., one target.
Hit: 6 (1d4 + 4) piercing damage.
Hard light Shield Bash. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature.
Hit: 6 (2d4 + 2) bludgeoning damage. If the target is a Medium or smaller creature, it must succeed on a DC 15 Strength saving throw or be knocked prone.
Zero Rifle. Ranged Weapon Attack: +10 to hit, range 100/300 ft ., one target.
Hit: 16 (3d8 + 4) cold damage, and the target must make a DC 16 Constitution saving throw or lose 10 feet of movement. Any creature critically hit by a zero pistol by Isumi must succeed at a second Constitution saving throw or become stunned by the intense cold for 1 round.
Parry. Isumi adds 3 to her AC against one melee attack that would hit her. To do so, Isumi must see the attacker and be wielding a melee weapon.
Combat Gear arc grenades (2), gravity grenade (5d6 force, DC 15 or fall prone), inferno grenades (3); Other Gear +1 invulnerability hide armour, hard light shield (+2 AC, cancels magic missiles), zero rifle, mwk bone dagger, thoracic nanite chamber (mark I, +2 CON, fitted), filter mask, batteries (7)