Freya doesn’t make that much of a noticeable difference to Telly’s minion damage - they just go from weak to still weak.
Freya really comes to the fore either as a stall (to buy time for average or slow heroes to be ready - minion health plus defence buff at fast fills this role very well)…
Or with higher attack minions like Puss, QoH or Delilah (I have all three maxed, they play together really nicely).
I’ve often run Delilah and Freya in a 3-1-1 and they’re very effective together like that.
I love my Mok - he hits huge and his damage to your own team is really low… You’ll barely notice it, but it’s useful with beserkers (increases the attack of beserk status heroes) and in a couple of other niche cases.
He’s not viable on defence very often but that’s not particularly important.
Khiona… Beserk is great, her snipe may not be huge but there’s some significant synergy potential there.
If you wanted to build a longer term team… Mok and Khiona together as the 2 in a 3-2 or 2-2-1 where one of the other heroes is a spirit link (Wilbur or Aegir, realistically) can create a scenario where you wind up dealing huge damage.
Khiona plus Wilbur giving you spirit link means that beserk gets ratcheted up quicker on the heroes either side of Khiona - Mok might be one (since AoE benefits the most from it) and if you’re on the last turn and beserk isn’t maxed yet, firing Mok will make sure it is!
In fact, having a spare Guardian Kong (2 maxed) that team would probably roll something like Wilbur - Mok - Khiona - Kong#2 - healer
(For fun, I just ran this team on farming… Headshot 3 waves in a row, including boss wave )
I’d definitely do all three (Khiona is on my list of purples to consider next, purely because I have two maxed Wilbur’s and I’d run one with Khiona and Mok - the other always runs with BK and Guardian Kong).
Which to do first kinda depends on what you feel you’re lacking… Freya buys you time and improves durability, Mok deals punishing damage and Khiona provides boosted attack (preferably to AoE attackers!)