Warder and Spells Strategy (level 49)
The most important spells at this level are Spirit of Kashek (new warder), Vigor of Zehkes (warder heal) and Spirit of Vermin (pet proc). You will also want Frost Shard (upgrade to Ice Spear, only available in Plane of Knowledge), Spiritual Brawn (atk and HP buff, in Shadowhaven), Raging Strength (replaces Spirit Strength), Protect (replaces Turtle Skin), Frenzy, Invisibility and Counteract Disease. Listless Power is only of any value in PvP; Invigor is close to useless.
These are significant updates to your existing line of buffs, warder and attack spells. Frenzy is a short duration self only stat buff that you should have cast on yourself all the time in combat; fortunately it lasts a lot longer than Fleeting Fury at around 10 minutes. However, the recast time for Frenzy is very long, so you will almost certainly want to dedicate a slot to it; if you still have Fleeting Fury memmed, this should replace it. Frenzy also prevents you casting any spell for 30 seconds, so it is best cast after combat starts; at this level, you should only very rarely be interrupted. Invisibility is extremely useful for safe travel, but won't cast even slightly reliably until your divination skill exceeds 150 (and more). Use Flash of Light to practice divination; you can cast it on your warder or a corpse in a safe spot. Counteract Disease is much more important than it sounds - as you fight more caster mobs, you will find yourself getting slowed; Counteract Disease can remove a slow.
One warning about Vigor of Zehkes; it is less mana efficient than Yekhan's Recovery, and even more so if you still have a Mana Preservation II item, which will benefit YR but not VoZ.
At this point I self buff with Inner Fire, Protect, Spirit of Ox, Raging Strength, Spirit of Monkey, Spiritual Brawn, Spiritual Light and Spirit of Wolf at all times. During combat, I add Frenzy to that list. Inner Fire doesn't add much, so you may choose to drop it. My warder is buffed with Inner Fire, Protect, Raging Strength, Spiritual Brawn, Spirit of Monkey, Spirit of Wolf and Yekhan's Quickening. Again, you may choose to let Inner Fire drop.