Referring to the myriad of ways of manipulating liquidity on-chain: flash swaps, flash loans, etc. No whales necessary. Remember that in the case of AMM trades, it’s only necessary to manipulate the price for an instant of time. This is virtually risk free. This happens literally every day on-chain.
The problem you’re missing here is that (absent additional smart contract controls) these two are equivalent, you are asking for unilateral powers and do not even realize it.
This approach is exactly the problem. Again, integrating a protocol only begins at whitelisting its entry points. Without intimate knowledge of how each protocol actually works at the smart contract level, you are asking to get burned.