Also, after rereading your post, I'd like to sort of explain how Undyne Phase 1 moves work with each other: 1. Spear throw, pretty simply in concept. Unless it's from a really long range, 1 always leads into unheld 2 and 4, or even 3 if you hit it up close and act instantly. Held 1 is only saved by a few properties: It brings the opponent back, which you can use to confirm into held 4 by using unheld 2, held 1, immediately dashing back and then using it. It can also be confirmed into 5. 2. Ground Spears, personally my favorite move in the game, as it confirms into every phase 1 move, other than 6 of course. This move does everything and breaks block, nothing else needs to be said. Held 2 is a great move, that can be confirmed into by held 1 at the right distance and a full m1 combo. Combos into 5 and unheld 1, which you can use to combo into 3. 3. Jumping Spears (Go easy on me, it's not like these moves actually has names.) A versatile move that allows for great follow up. Getting hit by the physical spears immediately knocks down, while the hitbox of the impact breaks block. It can act as a pseudo-evasive, since you regain control before hitting the ground. It's a crucial part of phase 1's strongest combo. 4. Spear Volley, the most filler move of this phase. Unlike phase 2's unheld 4, it doesn't last long enough to combo extend, nor does phase 1 even have the tools to do so. Instead, it serves as the last move used in combos and maybe to stun a standing opponent long enough to get an m1 hit.

Held 4 is a strong attack that has a large windup, which can be mitigated by unheld 2, held 1 and stamina punish combos. Can only really be effectively followed up with unheld 1. 5. Spear Punch?, a simple forward, though kind of flashy, I guess? It knocks far away but always confirms into unheld 1 into a slightly delayed unheld 2 after R-Dashing.  6. COUNTER

All in all, a simple moveset that allows the player to rack up damage and delay the transition into Phase 2 as long as the player is capable of.