At the start of each battle, this Hero is immune to new status ailments for 6 turns. In battles with multiple waves, the effect is refreshed at the beginning of each wave.
Special Skill: Arcane Blast
Deals 220% damage to the target.
The more mana the enemies have, the more damage they will receive, up to 250%.
The target automatically casts Mindless Attack on a random ally when mana is full during 3 turns.
All-In-One Reference, courtesy of @Lumi tap on image to view it fully
Or: How many summons are needed to get an Epic Challenge Event Hero?
It’s important to remember that Challenge Event Heroes have EXTREMELY low summoning odds. No amount of summoning will guarantee a Challenge Event Hero.
On average, in a 10-pull, you have a 25.1% chance of summoning Merlin.
But that statistic can lead our minds astray in exactly how our odds play out as we continue summoning.
Some useful insights:
50 times out of 100, you’ll get Merlin by pull 24 (6,400 gems)
94 times out of 100, you’ll get Merlin by pull 100 (26,000 gems)
99 times out of 100, you’ll get Merlin by pull 160 (41,600 gems)
Putting that in Perspective
50 out of every 100 people won’t get Merlin by the 24th pull
If 1 Million players each summoned 24 times, 500,000 of those players wouldn’t get Merlin
6 out of every 100 people won’t get Merlin by the 100th pull
If 1 Million players each summoned 100 times, 60,000 of those players wouldn’t get Merlin
1 out of every 100 people won’t get Merlin by the 160th pull
If 1 Million players each summoned 160 times, 10,000 of those players wouldn’t get Merlin
More Insights & Reading
I highly recommend reading these two threads for more information and context on summoning odds:
If you’ve read them a million times before, you may consider reading them again before deciding on your budget for summoning. A little time spent deciding on how much money you want to risk on summoning goes a long way to avoiding disappointment, frustration, and regret later.
His special is unique and cool in forcing an opponent hero to attack their own team. I believe there is a 5* purple coming with season 3 that includes a similar aspect in their special.
Personally, I really like Merlin in the 4* arena… No he doesn’t get into my raid teams anymore (used to be a staple) but thats because I am mainly raiding 4300+ TP enemies…
In 4* tournaments he comes out for the purple stacks as I firmly believe that mana control is one of the best META in the game, particularly in the 4* arena!
His damage is pretty good & the sniping damage he deals is also solid. Unlike all other comparable purple snipers (Most common one I see is Gafar), Merlin controls mana via the mindless attack & also scales the sniping damage with more mana (i.e. rewarding you further for good targetting skillz)
He’s not a defensive hero, as with other mana controller cases, because the AI sucks at both targeting and timing… however his place is definitly in an offence purple stack! even is good as the “off-colour” / “minor” colour in say a 3-2 or a 4-1 or 3-1-1 lineup for the sniping & mana control.
I just got Merlin in this event. At first, I was pleased, as I only did a handful of pulls, and at least it was one of the event heroes, and one that I didn’t have.
Then I noticed he’s Average speed, which is a bit of a disappointment. All this time, I thought he was roughly equivalent to Hansel, who I do have, and who is Fast speed.
You know what other Dark hero is Average speed and Wizard class? PROTEUS. And since I have SIX of him (three leveled, a fourth in progress), I’m struggling to think of any good reason why I should even bother leveling up Merlin.
Titans? I have Ursena, so I let Yellow titans fire their specials and reflect the damage back, I think that is far better than the small damage and Mindless Attack on itself that Merlin would make it do.
Raids? Again, with Proteus available, why would I ever take Merlin?
War depth? As already noted, I’m in the somewhat privileged position of having enough of Proteus to level up to eventually have one for each war attack.
While I don’t generally think Merlin is a BAD hero, for my specific circumstance, he doesn’t seem to be worth leveling up. The only positive I can see is the fun factor, and while that might be entertaining, I don’t know that I can justify putting him above the pure awesome effectiveness of just leveling another Proteus instead.
I think Merlin is great for 4* raid tournaments and events, akin to Hansel in green but on average speed. He pairs also nicely with Proteus for mana control. I have two maxed, and used them quite extensively when I was a beginning-to intermediate level player. Nowadays he sees less action, although I still sometimes take him with me those 4* events.
But I do have Hansel LB+20 and really like him and use him all the time, even over some of my green 5* . I was hoping that Merlin could become a useful hero for me. Only have Sartana and Obekan as 5* purple.
Merlin will be as useful as Hansel in my opinion! Just that Merlin is average to Hansel’s fast, but then Merlin brings mana back to zero go for it I say!
Another perk is a lot of easily obtainable mana controllers (a disproportionate amount really) are yellow. It makes yellow mobs and bosses slow going when you need that control so Merlin slides in there nicely.
Special Skill: Arcane Blast
Avoiding Overspending & Heartache 
