Since you can't get mareep in firered trade one from emerald.
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You can't you must trade from Emerald, the Lost Cave is programmed to have mareeps but it's an event that Nintendo never had
You can get Ampharos by evolving Flappy which you can get at route 222 (with Pokeradar) but it's uncommon.
In Pokemon firered you can't, but in Pokemon leafgreen you can get it then trade it to Pokemon firered.
Flaaffy evolves into Ampharos at level 30
There is a move tutor in the Frontier Access who will teach ampharos Outrage for 48BP