Heart of Leviathan: After destroying either side pod to open up the core,the remaining pod’s effect will kick in.Iirc,one drains your DT while the other absorbs all orbs in the room (?).One should take that into account during that fight.

Greyon: After first defeating him and acquiring the Quicksilver style,one can use it to negate Greyon’s own time-delay effect.This could prove tricky to correctly use,but it could be useful for some players.

Doppleganger: If one manages to open all lights in the room before he shuts one down with his projectile attack,then he’ll be stunned for a much larger period of time than when only one light hits him.Note that this is mostly possible during the first half of the fight and/or at lower difficulty modes,though some players may still pull it off anywhere.

Arkham: This isn’t really a tip of sorts,but an objection to the Recommended Style.As Arkham forbids all DT usage during half the fight,a player would effectively be “styleless” for that whole part of the fight.I understand it would surely be a blast for the first half,however I’d suggest adding a second style as Recommended.Just my personal opinion,nothing more.
(Note: The Gunslinger style would be rather useful,as 1. it helps with Arkham’s summons and 2. it makes Vergil attack ceaselessly,as he attacks whenever you do,firing included.Still,just personal taste.)

About Agni & Rudra (as mentioned above):Those are actually deities in Hinduism,Agni being of fire and Rudra being of wind.Just a semi-informative note there.

Again,my thanks for the great guide and I sincerely hope I’ve been of help. :)