How did Ati connect to Ruin

[Solarserpent]

In Secret History we see that Kelsier could not connected to Preservation without aid. And when he did so he was still unable to wield it well. I assume that over time his mind would move more in line with Preservation and be more capable with its power. So with that in mind, how did Ati connect to the Ruin Shard to begin with. Hoid said that he was a kind and generous person (this doesn't sound like a person who was attuned to ruin). did he have help to Connect to its power. And if so did he have trouble controlling it until he was changed by the shard's intent. 

[Calderis he/him]

The idea that a kind and generous person can't be connected to Ruin is somewhat undermined by the ending of HoA. 

[Alderant she/her]

30 minutes ago, Solarserpent said:

In Secret History we see that Kelsier could not connected to Preservation without aid. And when he did so he was still unable to wield it well. I assume that over time his mind would move more in line with Preservation and be more capable with its power. So with that in mind, how did Ati connect to the Ruin Shard to begin with. Hoid said that he was a kind and generous person (this doesn't sound like a person who was attuned to ruin). did he have help to Connect to its power. And if so did he have trouble controlling it until he was changed by the shard's intent. 

Ati was present at the Shattering, along with the other 15 shardholders, and took up the Ruin Shard as part of that process, presumably. He didn't have to connect to Ruin.

Kelsier on the other hand, suffered from two problems: one, he was dead, and therefore he was only in the Cognitive Realm (a Shard exists on all three realms at once, a connection is hard to form when you only connect to one aspect), and two, he was more Connected to Ruin than Preservation. Those two were opposites, and something so strongly Connected to Ruin could not be Preservation. He overcame that by shattering the jar of liquid, which allowed him to forcibly Connect to Preservation, but the link was tenuous at best, hence his difficulty in wielding Preservation.

[Oversleep]

Basically, the fact that someone is kind and generous does not mean that person is not destructive. Or that they doesn't view entropy as the elemental force driving everything. Or that they don't view the ending as the thing that defines and completes the thing. Or...

And so on, and so on. People are generally complicated beings and they cannot be reduced to two traits and their traits could be what people can see as contradictory.

2 hours ago, Alderant said:

He didn't have to connect to Ruin.

We don't know that.

[Yata he/him]

50 minutes ago, Calderis said:

The idea that a kind and generous person can't be connected to Ruin is somewhat undermined by the ending of HoA. 

Extremely agree with Cal.

Ati could be' a really depressed Person or a pessimistic and still be' a kind and generous Person.

Ruin isn't only a rampage killing macchine.

It's the rapresentation of all the entropy in the Cosmere. The mourderous monster we saw is an extremistic view of itself.

It's the same thing with Preservation, I honestly can't believe Vin would freeze everyone in a Perpetual statis but It's what Preservation would do without opposition.

Returning to your main question, as Sazed's pain and bad moment connected him to Ruin enough....the same could be' true for everyone.