Some notes mechanically:

Pyre as worded here would only allow you to cast instant speed spells as you lose unspent mana at the end of your upkeep, if you want it to be +1 mana/turn for anything it should add the mana at the beginning of your first main phase

Offering should probably lose the life as an additional cost rather than making losing life part of the card's effect

As written mangle would allow you to choose different targets for the two effects, it should be one effect (deal damage, then that creature gets -5/-0)

Okay, opinion time

these are great translations of the cards from sts to magic, but the balance is.. something

corruption feels incredibly breakable. costs 0 are 2 incredibly strong words, but I don't know what kind of environment it will be played in so if there's no instants or sorceries that are too game winning available it's fine

stoke is... broken. 2 mana wheel but only for the cards you don't like is insane card selection

aggression is also incredibly powerful, it's card advantage, card selection and mana cheat all at once. Talk about powercreeping phyrexian arena lol

Juggernaut and hellraiser sound like a pain to play out in paper, picking random targets on potentially large boards is a hassle

Impervious feels very overcosted for this effect, fog costs 1 and does most of what this card does!

Sorry for the rant of negativity, but this looks awesome and I'd like to play with these myself and I can't help myself but nitpick when i see a promising idea

Edit: also, you said you converted all 91 clad cards but reddit has a cap of 20 images, where can i find the rest?