You’re on the right track, but I think you’re overestimating the benefit of Santa and Kunchen’s sturdiness in the face of their slow mana.
Here’s the exact numbers (I have a “Garanwyn’s private version” of @RedPython’s excellent analysis spreadsheet to which I’ve added the tiles-to-kill data and @Kerridoc’s intuitively very useful Sonya index).
Delilah is, like Ares, very dependent on her supporting cast for her utility as a tank. Her primary jobs are to keep snipers alive long enough to fire, and to act as a tile soak to prevent ghosting.
Delilah
- 5.2 tile average kill from a 3-stack, so she’ll take a 3-match and live
- The Fighter’s rez being “likely with high mana” is strongest on early boards, when most of the damage she’s taking is tile damage. She’s scary as a 5+20 fighter for this reason–she can take the hardest hit you can throw, then pop back up and heal everyone and minion up.
- Don’t forget that those minions also act as a running DOT chewing away at the offense every turn. It’s not huge, but it stings.
Kunchen is also a supporting cast kinda tank. He’s super durable, but his slow mana means that the offense will get to fire specials on all but the worst boards. This makes him relatively less desirable.
He’s actually most useful against yellow titans, where flasks overcome his mana speed, and his effects are huge. Basically, bring 2 slots of mana pots, 0 slots of health pots, and leave Wilbur at home.
Kunchen
- 6.7 tile kill, 7+ with emblems. That’s kinda scary.
- You’re right about him being RP-proof. See @Kerridoc’s comment for how to work Kunchen over with a Wilbur team though. Perhaps the most interesting threat countered by his resistance is Athena.
- Slow mana means he can’t affect the fight directly until many tiles in. His biggest benefit early is he’s sturdy enough to prevent ghosting for a long time.
- Super vulnerable on average boards to Jackal stacks
- Super vulnerable to the yellow mana cutters like Onatel, Leonidas, Chao, Grettel early on, but cleric talent reduces this vulnerabiity somewhat. Bring 2, though, and he probably never fires.
- Once he fires his special, it’s probably game over for the offense–not the least of which because if he’s lived that long, the offense has had a terrible board and the defense has all kinds of specials ready or already fired.
Santa is also a supporting-cast tank. Which makes the 3-turn-only debuffs really unfortunate. He’s super durable, but his slow mana means that the offense will get to fire specials on all but the worst boards. This makes him relatively less desirable.
Santa
- 6.9 tile kill, 7+ with emblems. That’s kinda scary.
- His special only does 118 damage to an average target. It’s basically an AOE slash attack.
- He’s slow mana, so while his special is very unpleasant to get hit with, there’s every chance that countering offensive heroes will be charged on even marginal boards
- Blue has a high concentration of heroes who counter Santa (Kiril overwrites everything with a heal thrown in, Magni overwrites the defense down, Athena and Isarnia counter with a more-than-offsetting defense down of their own)
- His effects only last for 3 turns; it is relatively likely that no defensive special will fire in that window. This is very unfortunate. The -attack is, therefore, the really useful debuff
- Monk’s talent at least resists mana slows (but not mana cuts)
Personally, I prefer Delilah by a lot. She’ll live through a lot of boards against a 3-stack, she’s got that super-frustrating rez, and when she fires, there’s every chance that the rest of the defense will live long enough to use their specials.
Santa and Kunchen will live a long time and prevent ghosting–so they will very much frustrate slow-mana attackers. But average or faster attackers should all be charged on even very iffy boards before Kunchen or Santa fire.