Their issues are mostly in the mana base and will need updating to local meta
If a Clue you control is already a creature when Tangletrove Kelp's second ability resolves, Tangletrove Kelp's second ability will overwrite any previous effects that set that creature's power and toughness to specific numbers
It's worth noting that the codes can occasionally be fairly fiddly when it comes to capitalisation
Tomb of Annihilation doesnt need to go in your deck, and venture into the dungeon effects are plentiful, meaning you can conjure The Atropal almost as an afterthought
The worst part is that now that these cards are integrated into the general population (Portals cards were never originally intended to be legal) it creatures the absurd rule that flying creatures can't block creatures with horsemanship, which makes no sense
Once at least four creatures have died, you don't ever even need to play Sephiroth, as every death will drain an opponent for one life