Understand the skill menu's UI?

The most important feature I had in mind was that you'd have to invest in a T1 skill to see the T2 skill of that tree.

Lemme know what questions you might have about it.

Am I missing something ?

Yes!

Hi Al Est!  The target of the Add Triggerable effect is the weapon itself, not the player, which... won't work.  This is because the default target for most Effects is the actor the Affix is applied to.  The Affix is applied to the weapon.  There's no target defined for Add Triggerable, and judging from how it works for players (it always targets the player when the Affix is applied to the player), it's adding the Triggerable to your weapon.  I don't know if there's any way to modify the proc to have a triggerable work with a weapon in that way.  I don't know if triggerables work with weapons at all.

The only way I can imagine this might work is if you add a Cast Skill effect to the weapon which casts a proc that adds the triggerable to the player (and removes it on an Event_End).  I can't guarantee this will work.  You'll also want to ensure that the triggerable only gets added once and gets removed, otherwise you'll have problems.

Oh man, this sounds exciting!  But first I have to get some time to actually play the game!

I think Aherin's right.  It's important to ponder the why for a good long while.  Then the what.  Then the when and the how and the who.  In the meantime, it might be good to spend some time just learning GUTS and seeing what's possible with it and what isn't.

Does anyone know of some easy-to-use "dependency checker" for TL mods? 

That would be fantastic.  Someone with coding skills should write a program to do this!

Mmm... dunno off the top of my head.  Maybe post the text of all the related files here so someone can take a look at it?  By related, I mostly mean skill.dat, any effect.dats, and layouts.

I would open the mod folder (instead of using GUTS) to explore the files that were changed in the Death Ritual mod you used.  There's likely something that needs to be changed back to vanilla for your Death Ritual skill to work correctly.  I'd check the Skill Tree Override, the Skills, and the Stats in that order.

Also, the way Death Ritual works is that it sets a variable (a stat) that augments the effects of the other three skills.  The other three skills all have either Effects or Stat Watchers that are dependent on that variable.  If any of those skills or their connected Effects were changed, that would prevent Death Ritual from working properly.