D&D 5E Warlock / Sorcerer build. Thoughts?

PC concept I am playing with, gamed out to level 13. Main attack is eldritch blast (of course lol). DM has allowed me to pick up spell secrets as a Warlock Invocation of the Seeker.- With twinned spellmetamagic, this can be used with eldritch blast ? I can't see why not but if someone thinks otherwise love to know.
If you can, I can shoot someone 6 times for 1d10+10 *6.. Mwhahaha LOL

Gabriel Starbreeze (CG half-elf)
Sorcerer 8 (Sea) / Warlock 5
-------------------------------------------------------------
Armor Class 17 (mage armor)
Hit Points 83
Speed 30 ft.

STR DEX CON INT WIS CHA
10(+0) 18(+4) 14(+2) 12(+2) 10(+1) 20(+5)
Saving Throws Wis +6, Cha +10
ASI +3 dex, +3 Cha
Skills Arcana +7, Athletics +5, Insight +6, Investigation +7, Perception +6, Stealth +9
Senses darksight 120’, passive Perception 16
Languages Celestial, Common, Elvish, Sylvan
------------------------------------------------------------
Background. Far Traveller
Tools. Navigator’s
Eldritch Invocations. agonising blast, devil sight, spell secrets
Pact Magic (Chain). Learns find familiar. Gains a sprite as a familiar.
Metamagic. Extended, Twinned
Curse of the Sea. Adds charisma modifier to spells that deal lightning damage.
Spell Secrets. Your patron has revealed to you arcane secrets. When you cast a spell that deals acid, cold, fire, force, lightning, necrotic, radiant, or thunder damage, you can substitute that damage type with one other type from that list (you can change only one damage type per casting of a spell). You replace one energy type for another by altering the spell’s formula as you cast it. When you cast a spell with a spell slot and the spell requires a saving throw, you can change the saving throw from one ability score to another of your choice. Once you change a saving throw in this way, you can’t do so again until you finish a short or long rest.
Shielding Aurora. Starting at 1st level, you can invoke the Seeker’spower to protect you from harm. As a bonus action, you create a whirling aurora of brilliant energy that swirls around you. Until the end of your next turn, you gain resistance to all damage, and if a hostile creature ends its turn within 10 feet of you, it takes radiant damage equal to your warlock level + your Charisma modifier. Once you use this feature, you can’t use it again until you a short or long rest.
Watery Defense. You gain resistance to fire damage. You also gain the ability to defend yourself by momentarily assuming a watery form. As a reaction when you are hit by an attack and take bludgeoning, piercing, or slashing damage from it, you can reduce that damage by an amount equal to your sorcerer level plus your Charisma score, and then you can move up to 30 feet without provoking opportunity attacks. Once you use this special reaction, you can’t use it again until you finish a short or long rest.

Sorcerous Origin. Sea Sorcery
Sorcery Points ( 8 ).
Sorcerer pellcasting: 1st-level caster (DC 18).
Cantrips (at will): blade ward, light, mage hand, mending, presitigitation
1st (4): detect magic, shield
2nd (3): darkness, misty step
3rd (3): counterspell, fly, haste
4th (2): dimension door, greater invisibility
Patron (the Seeker)
Warlock
Warlock Spellcasting. 5th-level caster (DC 18).
Cantrips (at will): eldritch blast, message, minor illusion
3rd (2): counterspell, darkness, dispel magic, featherfall, hex, misty step.

Profiency +5
Actions
Eldritch blast. Ranged spell attack attack: +10/+10/+10 to hit, reach 120ft., one target. Hit: (1d10+10) lightning damage.

You can't twin Eldritch Blast, per errata to twin spell.

You can quicken it, however.

TwoSix said:

You can't twin Eldritch Blast, per errata to twin spell.

You can quicken it, however.

Click to expand...

This.

Also, while the idea of adding the same attribute twice for damage seems legit by the book, I would not let it fly in my games. It really feels to me allowing this would send the rules interactions somewhere out of place, as if you were being rewarded twice for the same thing. Anyhow, if this curse of the sea feature is based on the draconic bloodline elemental affinity, I guess it would be limited to only once per casting of a spell, so it would only add to one of the eldritch blast attacks, and would be applied again once for the second casting of a potential quickened eldritch blast.

Edit:

I just saw that:

Amatiel said:

Watery Defense. You gain resistance to fire damage. You also gain the ability to defend yourself by momentarily assuming a watery form. As a reaction when you are hit by an attack and take bludgeoning, piercing, or slashing damage from it, you can reduce that damage by an amount equal to your sorcerer level plus your Charisma score, and then you can move up to 30 feet without provoking opportunity attacks. Once you use this special reaction, you can’t use it again until you finish a short or long rest.

Click to expand...

Is this really meant to reduce damage by an amount equal to sorcerer level + Charisma score, and not modifier?

One other thing I noticed...why the intentional nerf of your spells known? You get 9 sorcerer spells and 6 warlock spells, but you have three spells (darkness, counterspell, misty step) known for both classes. Remember, you can cast sorcerer spells known with warlock slots and vice versa. (This works the same for every multiclass spellcaster.)

wasn't sure about the spells known thing across multi-class characters. Good to know. Ah, Quicken it is then. Oh well
The Sea Sorcerer is from UA_Sorcerer
https://www.learningdnd.com/resource/unearthed-arcana-list/
https://media.wizards.com/2017/dnd/downloads/26_UASorcererUA020617s.pdf

Amatiel said:

wasn't sure about the spells known thing across multi-class characters. Good to know. Ah, Quicken it is then. Oh well
The Sea Sorcerer is from UA_Sorcerer
https://www.learningdnd.com/resource/unearthed-arcana-list/
https://media.wizards.com/2017/dnd/downloads/26_UASorcererUA020617s.pdf

Click to expand...

If the table is ok with it, all good - just be wary about rocking up and blowing everyone out of the water (pun...), especially using material that's still being tested. I know our players would find it amusing once or twice, but if encounters become trivialsed due to one player's character, the game can get pretty dull for everyone else. Everyone wants to be the snowflake!

My first thoughts is "There's a character optimization forum for this"

My second thought is "No, you can only twin a spell that can only have one target, not any spell that only is targetting one target."

My third thought is "Nice thinking on the double dipping Charisma for Lightning spells. Should work, since Oathbreaker's Aura of Hate and the Warlock's Lifedrinker get along fine."

Have you also considered Tempest Cleric 2/6, to maximise Lightning damage 1/2 per short rest?

EDIT: Your description of Spell Secrets is off. There's a key part missing: "when you cast a spell with a spell slot [...]"
So unfortunately, no turning EB into Lightning Blast.

I'm curious where you found spell secrets as a Eldritch Innvocation, only place I found it is for the Lore Mastery Arcana Tradation in unearthed Arcana.

Edit: Never mind I re-read your introduction again

Thoughts:
All i see are a bunch of stats. No description, no background, nothing that makes this a character. At least you included a name though.

TwoSix said:

You can't twin Eldritch Blast, per errata to twin spell.

You can quicken it, however.

Click to expand...

What if your PC is below level-5 and just shooting 1x ray (technically shooting at one target only). Then they can be twin spelled doesn't it?

Mine is not a Sorlock but a Warcerer - having Warlock - X / Sorcerer - 3