This is the #1 requested feature for GBA hacks. The hack implements the NDS-era mechanic where moves are categorized by the icon (red explosion for Physical, blue ripples for Special). This makes Pokemon like Crawdaunt (Physical Dark) and Arcanine (Physical Fire) actually viable.
Assuming you find a legitimate version of this hack (often labeled version 1.4 or 2.0), here is what the gameplay loop looks like: Pokemon Ruby Magma Nds Rom Zip
First, a crucial distinction must be made. The official Pokemon Ruby was a Game Boy Advance (GBA) title released in 2003. The keyword "NDS" implies you want to play it on a Nintendo DS emulator. However, there is no official DS remake of Ruby or Sapphire (that honor belongs to Omega Ruby/Alpha Sapphire on the 3DS). This is the #1 requested feature for GBA hacks
Therefore, "Pokemon Ruby Magma" is almost certainly a ROM Hack. Assuming you find a legitimate version of this
Based on community lore and scattered patch notes from the late 2010s, Pokemon Ruby Magma is a fan-made modification that typically features: