At best enchanter can play offtank, which is the second tank that usually is used to hold adds or aggro when the main tank dies. But Iruna is too simple a game, when we boss the only adds we have are like... 2 taran at Tarante or 2 globus at Matadora. lol. (If we had for example to fight Sianas and Mezzaluna at the same time in one boss fight, then off tank would be useful.) Then, paladin guardian skill draws all the aggro from every mob anyways. So, Iruna doesn't require the offtank unless the paladin dies often (which shouldn't ever happen).
The vit builds are really designed to enable solo, but it's uncharted territory I'd guess. 256 vit on my character hp wise was about 15khp. I have to double-check, but just from that it's obvious tanking through hp isn't our strongest suit. It's enough for me to choose to abandon hp xtals. (Nevertheless, I can max out at 30khp.)
Focusing on stoneskin does give endurance and tank ability, but we just cannot hold the aggro. Currently, nothing is working (at least for myself) to hold aggro 100% of the time or at least as well as full paladin. We also have to deal with the issue of lag because our survival is based entirely on one active skill versus paladin's large hp pool. If enchanter is lagging and misses a cast, they die (because our hp is far too low), and then the pt dies. Paladin can lag all he/she wants so long as the aggro stays on pally and the bishop is casting heal.
What I like is tanking without a healer, but how well it goes is usually dependent on the dps of the pt. Then, I have to deal with the issue of aggro leaving me for the dps members and being unable to draw it back. Like for example at garrel duo'ing with a sniper, we can defeat it in maybe under 10 seconds. However, 3 or 4 out of 10 runs garrel decides to target the sniper, and I can't draw aggro. So, sniper has to die. Then, I heal and we repeat the process until clear.
But garrel can sometimes just keep targeting the sniper even though my aggro loss is sort of low (maybe 30-45% chance of losing aggro), which is just annoying to my pt member. So, maybe, next time the sniper finds a bishop instead. It's an unecessary hassle making an enchanter to tank. I could tank just fine (losing the aggro most all the time), but my pt members, friends, guild would eventually all decide to look for a paladin. They'd even go through the trouble of making an alt Paladin just for farming because it's just that annoying atm in game depending on enchanter to tank in pt.
On the other side, Hwiz is a core member to pts because of their dmg and ability to provide mp to pt members. Enchanter can dmg just as well as Hwiz and provide mp. They can fill the same slot as Hwiz in pt. But this only applies if the Enchanter builds dps.
Making an even simpler list of pros v. cons..
dps
+ can pt
+ solid dmg
+ faster lvling
+ can still solo mq (depending on build)
- low hp
- (depending on build) low survival
- has to carefully choose training locations outside pt
tank
+ high survival
+ doesn't have to be picky about training locations
+ can solo mq
+ can solo bosses up to gankaku easily (xtreme xceptions and equipment choices allow more bosses)
+/- Player skill determines bosses that are soloable
- xtremely low dmg (in comparison to dps)
- slow leveling