I know there are a good number of new players and folks that don't pay too much attention the JP servers here, so here's a quick FAQ on the Skill Inheritance system. I thought it might be useful since it's the biggest change to the game in a long awhile.
What is Skill Inheritance?
PaD now gives the players the ability to 'equip' an active ability of a card on another monster. This ability costs new material monsters called 'Tans. Don't worry, the guerrilla they come from is pretty easy and relatively low level teams should be able to clear it. The monster that is being equipped must have come from a REM, must be at least 5* rarity, must be level 99, and must be fully Awoken. So no skill up materials, no descend monsters with good actives like Iza, etc. The process is reversible, so no worries about losing the card.
How does it work in the actual dungeon?
The monster will now have 2 Cooldowns. The long and short, once your original active charges, the equipped one will charge. Once the equip one is charge, it will become the only active available to you. Once you use either of the actives, both will recharge.
That kind of sounds like crap. I like my original actives, why should I care?
The Skill Inheritance system lets you offload situational actives like shields, boosts, delays, etc. onto monsters you'd want to use for their better stats or for their orb change actives. Even if you have absolutely zero use for another skill, the new cooldown effectively operates as a Skill Delay Resist. This means you can counter things like Zaerog Infinite's skill delay without wasting latent awakening slots.
List of commonly used equips:
Delays: Possibly the number 1 desired equip. Allows you to get around many different Descend mechanics like damage absorbs, resolve, etc. Also can just give you needed time before a big hit. Example Monsters: Orochi, Exa-Hydra, D/L Batman, Sun Quan
Damage Shields: Pretty self explanatory. Allows you to counter big hits and pre-emptive attacks. The difference is that Skill Inheritance lets niche shields like the Elementals become way more useful. Examples: Indra, Susano, Raphael, Genie.
True Damage: As hard hitting and high defense monsters like PreDras become more common, these have become more useful. Ones that hit all enemies are far more desired than single target. Poison accomplishes the same task. Example: Ra, Rodin, Neptune
Bind Heal: Most teams have bind heal, but occasionally some squads need it to get around specific leader or type binds if they don't have a natural healer. Examples: Isis, L. Meta, Amaterasu
Damage Boost: Many top tier teams do good burst without a booster, but to do enough damage to late game enemies like the Arena Kalis, this becomes extremely valuable. Examples: Slime Knights like Muse, Jewel Princesses, the Norse pantheon, Kanna, Izanagi
HP Heal: A relatively new trend. This kind of active is mostly used for multiple, so single player teams might not find it so valuable. Basically, this is for teams that stack heavy HP, but don't necessarily have the RCV to back it up. Examples: Amaterasu, L Zhuge Liang, Ceres, Angelious, L Meta.
D. Kali Board Change: What Rainbow team would say no to D. Kali? Example: D. Kali, Ichigo, Lightning, Christmas Kali
Gravity: Very Niche, but can get you out of tight spots by avoiding an attack that hits at certain HPs or getting around resolve. Examples: Hades, Hathor
Junk Clear: Many teams want to hold their board change for a burst attack. Skill inheriting a junk clear lets you deal with junk filled boards without wasting a valuable board change Examples: Board Changers, Mechanical Star God 1 series, Satsuki
